tossing around the idea of efi for my 235

Posted by: drummin52

tossing around the idea of efi for my 235 - 02/09/09 06:57 PM

After reading all these threads on here and a few other forums (stovebolt, hotrodders, etc) I began tossing around the idea of converting my 235 to electronic fuel injection. Currently I have a clifford 2/4bbl intake with a 4bbl adapter and holley 390cfm carb so I have the intake manifold covered for such a conversion. What parts would I need for this conversion. I would hope most of it would be able to come from donor vehicles as I live very close to a u-pull-it yard and can easily and very cheaply get almost any part needed. Is there a TBI unit that would bolt onto my intake manifold and be sized properly for a 235? Im good with electronics and wiring and have a good understanding of computerized engine controls so getting and making a ecm to work shouldn't be too much of a challenge.

List of current engine mods are clifford tube style headers and a H.E.I. Conversion (modified GM 250 distributor)
Posted by: 243

Re: tossing around the idea of efi for my 235 - 02/10/09 04:15 AM

drummin,

Here is a link to a good article on retrofitting an AMC 258 with a GM TBI. I bought a complete 89 TBI 350 for my CJ and then, while mocking up the motor, trans and xfer case I said to myself, "if a 258 fell into my hands in the next two days I would use that." And two days later it happened. So the 350 will live under the bench until the next project and the TBI is for the 258.

It is very ironic that I turned my nose up at hundreds of I6 cars and trucks over the last 20 years because I wanted a V8, now I can't find the next project because everybody has converted them to a V8!

http://www.bustedjeep.com/projects/junkyardtbi.asp
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/10/09 09:17 AM

thanks that was very informing
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 02/10/09 04:52 PM

I just bumped a thread back up that has a list of what you need from a donor. Good luck!" TBI on A 250"
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/10/09 05:47 PM

thanks

looks like I will be waiting for the local yard to have a sale so I can get what I need even cheaper. Currently looking at about 50-60 for everything I would need. Includes TBI unit, computer, wiring harness and all sensors (not really charged for sensors). I already have a gm 250 distributor on my 235, I hopefully will be able to swap out the inner parts so the computer can control timing advance.

My brother has a engine computer diagnostic tool and a tuner program on the laptop so I mess around with the program if needed. I believe I read that the vss and egr program need to be removed.

I have a friend that runs a laser cutter that once I design the tbi adapter will be able to cut me out the adapter out of 1/2" steel or aluminum.

I currently have a brand new holley 390cfm carb on my 235 but if I get this to work I will put it away for a future project or see if I can find a taker for it. Its already modified (jets and nozzles) to work for a 235/261.
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 02/10/09 06:52 PM

Sounds like you're starting down the road I started on about a year or so ago. Wave when you go by! \:D
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/11/09 03:16 AM

yeah hopefully its a good road to head down. I figured Im already doing alot of modifying to my 52 Chevy 3/4ton pickup, why not go a step further and add fuel injection to the 54 235 inline 6 thats in it. That should make it stand out just that much more at car shows and gatherings. 1 no v8, instead a engine, a inline 6 of the trucks era with a bunch of speeed parts and custom modifications like power steering and so on. Adding throttle body injection is just icing on the cake.
Posted by: Nexxussian

Re: tossing around the idea of efi for my 235 - 02/11/09 09:29 AM

drummin 52, welcome.

I read that you have an intake already and it's setup for a 4bbl.

I thought I should forward that it was suggested to me that if I wanted a few more style points I could do more or less the same thing with the substitution of 2 single barrel throttle bodies on a multi carb manifold (ie offy dual carb).

It was suggested that if you wired one throttle body up with the idle air control, plugged it off in the other you could run straight linkage between the two TBI units the computer wouldn't know the difference.

I mention this as you spoke of astetics being one of your motivating factors (since 2 'carbs' look cooler than 1 ).

If you are interested I will try to find where I was told that (it was on here).

I haven't tried this, I have a 1950 Jimmy with the OE 228 I have been toying with the idea of doing this with. That and moving that smelly gas tank out of the cab.

Of course that's not happening any time soon (too much other stuff going on at the moment).
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/11/09 11:31 AM

I agree, two 2bbl tbi units on a dual intake would look awesome, in fact this person is currently doing that. But since I already spent the money on the clifford intake and such, that is what I will stay with. Plus it will be easier to just have 1 unit instead of two and cheaper as I know the local yard has tons of 4.3L's with throttle body injection and the vehicles to get the wiring, sensors and computer off of.

Luckly I already removed the gas tank from the cab and installed a summit fuel cell under the bed, behind the rear axle. Another plus is I already have 10AN steel braided fuel line running up to the mechanical pump on the 235. All I would need is a external mounted pump somewhere inline and a little changing around under the hood to bypass the mechanical pump. Maybe mount the pressure regulator down by the mechanical pump, like on the frame, with a steel line for the return. I'm going to try to set everything up where I do not have to butcher my current setup so that if I go back to carburated I don't need to redo what is alread done.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/11/09 10:54 PM

A couple of notes..

1) mount the pump as close to the tank as you can with a EFI fuel filter before and after the pump (unless the tank has a pickup strainer - if so then omit the inlet filter. If your get the Earls AN to snaginaw adapters then you can use the GM TBI fuel filters same type that on the donor.

2) GM TBI's have the pressure regulator built in :).

3) The 4.3 TBI should be fine if you can tune the ECM. If you run the GM ECM it'll probably idle rich until its tuned.. kind of like Tom's truck when we did the impromptu EFI conversion at B'Ville last year. the cause was was a horrible vacuum leak that caused the MS to think the throttle was near WOT when it wasn't so it was dumping fuel in. It took some fast fingers to lean it out before it stalled.

4) holley sells a TBI to 4bbl adapter for about $30.

5) Er -6 line is plenty big. For low buck use a single braid hydraulic hose.. no need to spend $$$ on the fancy stuff. Both the feed and return need to be braided in case the return line ever plugs up the line pressure will rocket up > 50 psi.

Have you consider what your going to run for the ECM?

If you decide to run a MS with the GM '747 adapter board it just plugs into the GM harness with no modes and you can tune it with a laptop much much faster than guessing at a change and then burning eproms. :(-

Ask either Tom or myself if you need help...
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/12/09 04:51 AM

So I can go directly from the post fuel filter directly to the tbi unit? And then another line, size ?" comes out and runs back to the tank???

For the adapter I may just make my own as the clifford intake is quite simple, just 4 allen key screws hold the plate on. Just need to remove my 4bbl adapter. I have some 1/2" aluminum plate that I can have a friend cut the adapter out of for nothing except the cost to ship it to and from his work. I work daily on AutoCAD so a design like this should take 5 minutes at the most.

Oh and reading back through my previous post I noticed I said the wrong steel braided line size that I have, I ment to say 8an which I imagine will work just fine. The inner diameter is 0.438", 6an is somewhere around 0.343".

The eprom is the removeable chip correct? I will make sure I grab a few of them when I go to the yard.

For now I will try to run using just the computer that I get the TBI unit out of, if I manage to sell the holley carb to get some of what I spent back, I will look into getting MS.

Thanks Guys
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/12/09 11:48 AM

Drummin

The EARLS GM adapters to AN adapters are only available for -6 line.

There are 2 removable chips in the GM electronics

- eprom
and
- calpack

both have to be from a 6 cylinder app. otherwise the ecm will get pissed off.

I'd grab some eproms and calpaks from a 2.8TBI v6 and the 4.3 - with the 2.8 calibration and the 4.3 TBI it might be the best combo. Just make sure they are both from a '747 or '746 ECM.

fuel flow is... tank - pickup sock/inlet filter - pump - outlet filter - TBI (all -6) then TBI - submerged fuel return << very important or the fuel will flash when it enters the tank causing high pressue build up! return needs to be -6 as well.

Bring the TBI & fuel filter in with you when you get the adapters.

Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/12/09 05:06 PM

out of what vehicle (hopefully a 80's or 90's) can I get a externally mounted fuel pump from.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/13/09 05:15 PM

what should the specs be for the fuel pump (psi and flow amount)?

Im looking for a external mounted electric pump that I can get at the local yard.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/13/09 05:49 PM

Look in a mid to late '80's ford - they typically had external pumps.

90#/hr @ 20 PSI is lots for your app. (good for 180 HP NA).

Once important note EFI pumps like to push fuel, but are very poor at sucking - so the pump needs to be below the fuel level and as far back as possible. Some times the factory will put a low pressure boost electrical pump ahead of the efi pump to ensure the efi pump gets the fuel out of the tank. Look under VW jettas/golf's for this type of setup.
Posted by: pinebluffdude

Re: tossing around the idea of efi for my 235 - 02/13/09 07:36 PM

Thanks for this thread. I just rebuilt the carb on my 81 GMC 250
It has caused me aggrivation and I was just today wishing I could figure out a Fuel Injection Set up for that rascal.
Contrary to popular belief... Fuel Injection was not invented in the 1950s for the Corvette. In the Navy I ran a diesel generator that was designed in 1938 and it had TWO fuel injectors for each cylinder.
Good Luck with your projects. If I learn anything I will post it here.
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 02/13/09 08:22 PM

Trust what efi-diy is telling you. Last year at Speed Week we converted my carbed 270 GMC to Megasquirt controlled GM TBI in about an hour! Had it not been for a vacuum leak and a fuel line attachment problem we would have been cruzing Wendover! I'm closing in on my 292 project and it is only taking so long because I am learning it all at once, but I am learning it
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/14/09 10:38 AM

Yeah I read that thread, one of the ones that pushed me towards doing the conversion in the first place.

Im putting a list of everything I need to do this conversion and so far looking at a total of just under $150.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/14/09 11:10 AM

It will be interesting to know if the GM ECM can adapt itself enough with out a tune (real painful with eproms) to run one of these motors.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/14/09 02:54 PM

 Originally Posted By: efi-diy
One important note EFI pumps like to push fuel, but are very poor at sucking - so the pump needs to be below the fuel level and as far back as possible. Some times the factory will put a low pressure boost electrical pump ahead of the efi pump to ensure the efi pump gets the fuel out of the tank. Look under VW jettas/golf's for this type of setup.


now this I will need to work out. My current line has a up hill run before it gets to the filter. I have the stock mechanical pump for the carb which does fine at sucking the fuel from the tank all the way behind the rear axle. A rerouting of my fuel lines looks like it will be needed. I also will have to see if I can raise my tank a bit.

http://i175.photobucket.com/albums/w124/rockfan1815/fuel%20tank/100_0091.jpg
this pictures show what I mean. I would also need to fasten the fuel line to the bottom of the frame rail to decrease the up hill run.

I was also thinking of rotating the tank so the outlets are pointing towards the rear and mounting the pump on the frame to the side of the tank. I might use some 1.5" square tubing and cut 4 blocks so I can raise the tank up a little bit.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/14/09 03:05 PM

Another thing I have to figure out is the return and how Im going to do that. The 6an fitting on top is for a return, I have to check but I think there isn't a line down to the bottom of the tank. I could try and see if a I can get a plastic tube to fit through the fitting and reach the bottom of the tank, worth a try. The tank I got has a block of foam in it to prevent fuel slosh and splashing. Not sure if a tube would even be needed.

If I can't get the return to go back in through the tank, I have a few other ideas. 1 is to put a Tee in the line before the pre-filter and feed the return in before the filter. I could also use the second fitting on the bottom for the return, but I was wondering if it would be a problem with the fuel flowing back up through the return when the pump is off. I don't think there would but I figured Id ask.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/14/09 07:04 PM

Can you get your arm into the tank and remove the fuel return fitting? If so maybe replace it with a -6 m-m bulkhead fitting then after getting it into the tank use a -6 to 3/8 line adapter and install a length of 3/8 steel line to 1/2 off the bottom of the tank.

Hard to judge from the pix, it appears that if you mounted the fuel pump under the frame rail behind the rear axle it should be low enough. If its within say 3 inches of the tank bottom you should be ok.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/15/09 04:28 AM

I think that will work once I raise the tank up a bit

I will see what I can do with the return
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/15/09 01:29 PM

I took some 2inch square tubing and cut out 4 blocks. My plan will be to rotate the tank so the discharge is towards the rear. I will use the blocks I made to raise the tank up. The pre-filter (a -8an filter that I already have on the truck) will be mounted directly to the discharge of the tank with a -8an 90deg fitting, from there a piece of -8an hose with two -8an hose ends to the fuel pump, with a -8an to 3/8"npt fitting. From out of the pump I will use a 3/8"npt to 3/8" hose barb fitting and a short length of 3/8" fuel hose (rated up to 50psi working pressure, and 175 psi max pressure) to a post filter. From out of the post filter I will run some more 3/8" hose up to the engine compartment were I will use a piece of 3/8" steel hard line to run up along the firewall to the 4.3L TBI unit.

For the return, I will use another piece of 3/8" steel hard line in the engine compartment to run along the firewall (from the TBI unit, on the driver side, to passenger side, down to near the frame rail. From there some more 3/8" rubber fuel line along the frame rail to the return fitting on the tank.

I could run everything along the driver side frame rail, but Im trying to keep everything for the TBI on the passenger side, incase I ever have to change back to the carb. Im also keeping the computer on the passenger side kick panel so the fuel pump relay will be near there too.

Sorry for the long posts, I like writing/typing stuff out, helps me sort things out better.
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 02/15/09 05:10 PM

You are a doer and a problem solver. If it takes a little space to do show and tell so what? We read what we want here, there is no required reading. ( except my posts )
Posted by: big bill I.I.#4698

Re: tossing around the idea of efi for my 235 - 02/16/09 07:11 AM

If you have a fuel filler neck that is connected to the tank with rubber hose you can weld/braze/solder a steel line into the filler neck that is long enough to reach the bottom of the tank then connect the return line to it. This keeps you from welding on a used fuel tank.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/16/09 07:39 AM

no welding here, its a poly tank.

I will reach in the tank to see if I can feel a line running down to the bottom from the return fitting. If not I will come up with something. I would think just getting a piece of plastic/rubber tubing with a outer diameter the same as the inner diameter of the -6an return fitting and shoving the hose down from the top till it reached the bottom of the tank would work fine.
Posted by: Nexxussian

Re: tossing around the idea of efi for my 235 - 02/16/09 05:11 PM

I think he meant into a remote filler neck (like maybe at the fender / bedside where you would actually stick the fuel nozzle).

Are you running a trap door through the bed as it is now (to fill the tank)?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/16/09 05:34 PM

Yeah when I finish the bed, my plan is to use a trap door, but just to access the top of the tank as it has a fill cap on it.
Posted by: big bill I.I.#4698

Re: tossing around the idea of efi for my 235 - 02/16/09 06:57 PM

Yes guys I am talking about a metal remote fill tube that your fuel cap goes on and the remote fill tube is then fastened to the tank with a hose. such as you would find on many cars and some trucks. If you are using a racing type fuel cell with a direct fill this won't work.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/16/09 07:52 PM

came up with a wiring diagram
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/TBIWIRING.jpg
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/16/09 10:05 PM

The fuel pump needs a dedicated 20 amp fuse. Also the ground wires need to connected to the block to ensure a good ground. Other wise looks good.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/17/09 05:05 AM

here is a question, what is a electronic vacuum regulator valve. Im guessing something with the exhaust gas recirculation system as it shares the same wires. For my diagrams Im following a diagram for a 89 gm truck. I also have a diagram for a 90 s10 with the 4.3L which is similar as far as where the wires go on the connectors but has a few extra items on the diagram.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/17/09 09:28 AM

The S10 uses a inlet air temperature (IAT or MAT )sensor. The rest of the connections are for emissions purposes - not needed.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/19/09 06:37 PM

ok forgot the hot fuel module??? on my diagram, thats where I guess the 20A fuse goes to.

http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/TBIWIRING-1.jpg
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/19/09 07:01 PM

ftp://ftp.diy-efi.org/pub/gmecm/manuals/1227747/

Most installs don't need the hot fuel module. I installed a TBI 350 in a '83 malibu (my first efi effort) after 1 week I tossed the hot fuel module.

Normally the orange wire (power feed from the battery)to the fuel pump relay has a 20A fuse in series with the relay. My GM manual shows a 20 amp fuse.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/20/09 06:55 AM

So delete the hot fuel module (and assosiated wires) and wire the fuel pump to the same terminal on the relay that the gray wire comes out of and goes to the computer. Then change the fuse on the orange wire to a 20amp fuse, or do you mean make the orange wire to the relay seperate from the orange wire to the computer, and put a 20A fuse on that.

What is a hot fuel module? looks like a special type of relay to me.

So in total only two fuses are needed to do this conversion. A 10A hot in start and run and a 20A hot all the time.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/20/09 09:30 AM

Fuel pump wiring - power side

battery > 20 amp fuse > orange relay wire > relay > relay tan/white wire > fuel pump. The orange fuel pump relay wire does not connect to the ecm or anywhere else except the 20 amp fuse that goes to the batery.

You need 5 fuses to make this work correctly with a GM ECM:

a) 20 amp > fuel pump
b) 3 amp(sometimes GM used a 10 amp) ECM fuse connected to B1 & C16 hot at all times. This keeps the RAM memory alive when you turn the key off so the learned values are kept.
c) 10 amp fuse switched hot in run/crank connected to A6.
d) 10 amp switched hot in crank/run to power the injectors.
e) from the fuel relay tan/white wire a 1 amp fuse going to B2 << this tells the ECM the fuel pump power is on.

With megasquirt you need 3 fuses:

1) 20 amp for the fuel pump
2) 3 amp switched hot in crank/run going to A6 ( this assumes your using the GM to MS adapter board).
3) 10 amp switched hot in crank/run to power the injectors.

Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/25/09 08:55 AM

Thanks diy-efi, changed my drawings to show what you said. might post it later if I remember.


I am still planning to do the switch over, just waiting for a nice weekend (50's or higher and sunny) and/or a sale to go to the local yard and get what I need. I made a list of everything I should need from both the yard and summit racing.com

Total so far comes to about $200.

Good news, my brothers programmer/tuner already came with everything I will need (program/file wise) to make the changes needed to the computer. The 747 and 746 computer must be very popular unit. From what I read I need to take out the vss and egr.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/25/09 12:12 PM

Yep the '746 & '747 came on just about everything that was TBI from GM.

For sure the EGR needs to go, not sure on the VSS though. Are you running an automatic?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/25/09 03:15 PM

no auto, currently running a 3 speed saginaw but will be swapping it out for a T5 some time soon.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/25/09 03:58 PM

The VSS was used on some calibrations to lean out the mixture once cruising speed was reached. And to run the LU TC. If you want to use it, you will have to get an inline speedo cable VSS generator.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/25/09 04:58 PM

was the vss used on all vehicles or just some. I have two diagrams, 1 from a full size pickup and the other from a s10. The s10 shows the vss but the full size does not.

Im trying to spend as little as possible so more than likely the vss will be taken out. If I found a transmission with a electronic speedometer drive instead of the mechanical would I be able to keep the vss?
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/25/09 05:03 PM

If I found a transmission with a electronic speedometer drive instead of the mechanical would I be able to keep the vss?

Yes - but is your speedo cable driven?

It'll run without the VSS connected.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/25/09 06:43 PM

I will eventually need to get a speedometer for my truck. I have a auto-meter tach currently and have been looking at their speedometers that match the tach. They have both electronic and mechanical. If I found a T5 transmission with the electronic speedometer drive I would then get the electronic speedometer and then use the vss. If not then I would get the mechanical and ditch the vss.

If I run it without the vss connected, will it show a check engine light? I just can't drive a vehicle with a engine light on, bugs the hell out of me.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/25/09 08:32 PM

Re VSS - I'm not 100% sure if it will turn the CEL on. Why not ask Tom BOTP - he has a '89 parts truck thats still intact I think - ask him to unplug the VSS at the transmission and drive it - see what happens.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 02/28/09 05:49 PM

Post up your revised wiring diagram.. so folks can see its not that scary...
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 02/28/09 07:26 PM

http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/TBIWIRING-2.jpg


Should be going to the yard to get the TBI parts tomorrow. Then I will need to place my order with summitracing.com for the other needed items. Soon very soon. Im thinking of doing a tech tip on the conversion w/ Plenty of pictures.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/01/09 04:29 PM

OK got a harness, tbi unit and computer and most of the sensors. Working on getting the unused wires out of the harness.

Question, what should I do with the knock sensor? The vehicle I got the harness out of had a knock sensor in it (I got the harness from a 1500 Suburban, which had a V8, but its the same harness thats used with the 4.3L TBI. In that busted jeep link he mentions splicing the knock sensor into pin c14 to eliminate the use of a knock sensor, not sure what wire he means, the one coming out of the computer to the esc module or the one coming out of the esc module to the knock sensor.

A guy on stovebolt also says that I can use a GM 250 knock sensor.

Im just trying to find out what I need to remove and what I need to keep and if I need to go back to the yard and grab a esc module.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 03/01/09 04:44 PM

I'm going out on a limb here a little bit.. I guess that the '81 California 250's that had electronic spark control used a knock sensor. Since these motors never made it north of the border - its an guess at best.

If they did use a knock sensor - get a knock sensor and the ESC module for the '81 250 - they are tuned to the engine size. I'd keep the ESC module to ECM wiring and run the knock sensor.

Did this help?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/01/09 04:51 PM

yes it did, thanks
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 03/01/09 09:45 PM

It' helping me to. Do you want me to find and unplug the VSS on my '89 to see what happens?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/02/09 03:22 AM

thats up to you
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/02/09 09:14 AM

Just two lists of what I have so far and what I need to get, this way others can see what all is needed for the conversion

Prices are just what I payed
I picked up the following so far
-4.3L TBI Unit off a 90 s10 - $20
-Wiring harness off a suburban, had a v8 but the harness is the exact same as what is used for the 4.3L v6 in the full size vehicles. - $20
-Engine Control Module (ECM, computer, etc), serial 1227747, came out of a 5.7L v8 so I grabbed the eprom & calpak out of a computer for a 4.3L v6 (didn't take the computer because the model wasn't a 747 or 746). - $30
-Also grabbed a map sensor and coolant temp sensor as well.

I need to get the following and then I can get to work
- TBI rebuild kit
- TBI Adapter. Im thinking of just making one, design on CAD and then have the local machine shop cut it out of 3/8 or 1/2 steel or aluminum, I have some 3/8" aluminum plate at home so I might use that. I know they sell 4bbl to tbi adapters but this way I can eliminate a few gaskets and problem points and bolt the tbi plate directly to my clifford 2/4bbl manifold.
- External mount fuel pump, a post pump filter and some various fittings and 3/8" fuel line
- Eproms and calpaks for a 2.8L v6 to try a few different combinations of chips and injectors. Maybe I should check the computers in a 3.8L v6 and see if those chips will work as well, might be a better match.
- I currently have a 250 HEI distributor but it is vacuum advance, I need to get the parts to convert it to computer controlled.
- I also have to get a knock sensor and electronic spark control module (esc) off of a 250 inline 6, if I can find one, if not I will try the one for the 4.3. Was also thinking about parts from a 292 if they would work and I can find one.
- O2 sensor, not sure which one would be best, one from a 250 or a 4.3L
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/04/09 02:08 PM

just came across a link that may help others look for a suitable tbi unit if they are also considering going the efi route. Gives a list of what vehicle, the year it can be found on and the size motor it came on.

http://www.championparts.com/tbi_applications.pdf
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/04/09 05:34 PM

I finished sorting through the harness I got and updated my wiring diagram.
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/TBIWIRING-3.jpg


I also just bought the remaining parts for the conversion. Just waiting for my tbi plate to get cut out. First part I will ever have thats been cut by a water-jet machine. Amazing.
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 03/04/09 10:00 PM

Man, You're moving on this! Would you come finish mine when you're done? \:D
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/05/09 05:24 AM

Sure pay for my ticket to and from Nevada and I will have it together in no time. A vacation in Nevada sounds nice. How is the weather?

Here is my plan:
-I will be gitting my fuel system stuff from summit tomorrow, plan is to have the fuel system ready this weekend.
-Local auto parts store will have my tbi rebuild kit in today, installed before my tbi plate is done sometime within the next 7 days or so.
-Then I will install the TBI Unit on the intake and all the sensors on the block.
-Computer will be mounted on the passenger side kick panel in my 52 3/4 ton chevy pickup. Im going to cut all the sensor wires about 2' before they go into the computer, plug the connectors into the sensors and run the wires into the cab through the firewall to the computer. Engine wiring will be completely seperate from all the other wiring (lighting, accessories, etc).
-After I make the trip to the local u-pull-it yard, I will convert my distributor to be computer controlled. A question on this below.
-Last thing, I hope, I need to finish the first project I started, which is adding power steering. Im also waiting for a few other pieces to get cut out. Those pieces are the belt adjusters for the power steering pump and alternator. This way when I start it on the TBI I can let it run instead of having to turn it off to keep it from overheating (no belt driving the water pump or fan)



Question on the distributor - The distributor is out of a 250 inline 6, with the coil in the cap. My question is, since there aren't a whole lot of 250's in the yard, are any distributor parts from a v8 usable. I think they are somewhat the same aside from the 6 to 8 cylinder internal differences.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/05/09 06:43 AM

http://chevythunder.com/1227747_ecm_198892.htm found it while searching, post it for those who may want to see it. Its not the clearest but usable.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/05/09 09:14 AM

1 more question

Looking at some wire diagrams for my harness, what is or where do I terminate the crank in wire on C9. Looks like there should be a fuse inline. Does this get connected to the start terminal on the ignition switch or a terminal on starter solenoid?
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 03/05/09 11:25 PM

Yep your correct - a 1Amp fuse goes to the starter wire that comes off the ign. sw. Doesn't matter where you connect into it. What it does is force the ign. module to run on base timing during cranking.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/06/09 10:26 AM

Sweet....water jet guy just called and said my part is done (tbi adapter and belt adjusters for the p/s pump and alternator). Got my tbi rebuild kit yesturday. Might work on that tonight as well as making a mount for the computer.

Going to the yard tomorrow to get what ever else parts I need, hopefully I get everything Im looking for. Going to take a break for half the day and go to a car show at the local armory.

Now I just need a coolant thermostat housing with two 3/8"npt ports. Anyone know what else works on a 235 (261, 250, 292, etc)
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/06/09 04:47 PM

I'm kicking ass!

Got the TBI Unit rebuilt and got my stuff back from the water jet and my fuel system stuff from summitracing.com

Some Pictures
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0720.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0719.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0718.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0717.jpg
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/06/09 04:52 PM

I made an opps on the TBI plate. I need to weld a small piece on because I didn't make one of the sides long enough so currently about a 1/8" of the IAC chamber is exposed, making for a really bad vacuum leak.

Got my list ready for tomorrow to go part hunting.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 03/06/09 08:47 PM

Chris,

Don't forget to revisit your alternator size... you'll be surprised at the extra load the fuel pump puts on. Get an alternator off of a TBI donor vehicle.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/07/09 04:30 AM

Yup, was actually thinking of getting another alternator anyways, don't know what the specs are for the one I have now as the previous owner installed it. Plus I have more plans it the works than the PO had, like power windows, seats, door poppers, a nice stereo, etc.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/07/09 12:09 PM

got another computer, this time out of a Chevy 1500 with the 4.3L so everything matches. For those interested I have a spare 122747 ecm if anyone wants it. Just needs the chips.

I got a ESC, just need to get a knock sensor. I also got a EST to change the distributor over to be computer controlled timing advance.

Im working on the tbi plate, Tapping out the holes for the 3 tbi bolts. One the first hole, the tap snapped and broke off in the hole when just about through. Ended up driving it out with a chisel and a BFH. The other hole went great, on the last hole the tap was just to warn out and didn't cut the threads deep enough.

Still need to get a fuel pump, thinking it might be better to just buy a new pump as most of the vehicles that I know have external mounted electric pumps are from the late 80s to early 90s. Within a few weeks I should have something going.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/09/09 02:49 PM

got the tbi plate finished and mounted and put the tbi on as well. I have to shorten the 3 bolts for the tbi a little bit as they bottom out on the intake. Im pretty sure I will leave it in the position that it is in currently. Plan is to run 3/8" steel hard line up the passenger side of the firewall, over the engine to the drivers side and down and into the tbi unit. Probably best to wrap the fuel line in heat tape or something as it would be running over the intake and exhaust manifolds.

Also mounted the computer on the passenger side kick panel.

I need to get a throttle cable from the local yard, hopefully it will hook up to my Lokar pedal.

Some pictures
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0736.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0738.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0739.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0740.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0741.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0742.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0743.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0744.jpg
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 03/09/09 03:26 PM

Remember the TBI is a constant flow return system to the tank so the lines will stay relatively cool when the fuel pump is running.

Also be sure to use rosin core solder for any splices and double wall heat shrink, the stuff that has glue in it so it seals to the wire insulation. I usually us a double layer for under hood splices, small heat shrink just big enough to slip over the solder joint about 1" long - shrink it then slip a bigger diameter heat shrink over the smaller one once its cool. Make the bigger diam. shrink about 3" long this provides excellent support and sealling for the splice.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/09/09 04:50 PM

will do, thanks
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 03/09/09 06:19 PM

Looking good!! The TBI is located like we did on the 270. All those wires still spook me but I know I'm close to finally sorting that out when I get the MS done. It will be very interesting to see what you get from the GM ECM. Truly a junk yard dog in the best rodding tradition.
Posted by: Nexxussian

Re: tossing around the idea of efi for my 235 - 03/10/09 03:39 AM

 Originally Posted By: efi-diy
....Also be sure to use rosin core solder for any splices and double wall heat shrink, the stuff that has glue in it so it seals to the wire insulation. I usually us a double layer for under hood splices, small heat shrink just big enough to slip over the solder joint about 1" long - shrink it then slip a bigger diameter heat shrink over the smaller one once its cool. Make the bigger diam. shrink about 3" long this provides excellent support and sealling for the splice.


I use the Rosin core and the HD heat shrink (with the glue inside) but I had never thought of doing it as a two layer setup, sounds good, thanks.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/14/09 07:39 PM

OK, made some good progress today, I will post pictures tomorrow of what I got done.

I went to the local yard and got a thermostat housing off a 261 that has two ports so I can install the coolant temp sensor and keep my hot water heat for my clifford intake.

I got about 75% of the wiring done, most sensors are wired. Whats left is the power wires from the fuse block, distributor modification, fuel pump wiring, esc/knock sensor wiring and some smaller stuff.

I was reading online about others doing fuel injection conversions using tbi and what fuel pump to use. A bunch of mixed out comes with different pumps. The ford external pump got a lot of mixed reviews, some said it worked fine, others said it didn't provide enough pressure. I ended up buying a new pump from summit racing. I went with a Carter P5001 pump made specifically for TBI conversions, that supplies a max 20psi and 50gph. A bit more than I wanted to spend at $150, but everyone that used it was very pleased with it and I figured it would be better than a 20-/+ year old pump from the junkyard. http://store.summitracing.com/partdetail.asp?autofilter=1&part=CRT-P5001&N=700+115&autoview=sku
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 03/15/09 12:31 PM

At least you know the pump won't let you down.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/15/09 05:07 PM

As promised, PICTURES!!!
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0791.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0773.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0790.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0789.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0788.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0787.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0780.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0779.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0777.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0776.jpg

About 90% of the wiring is complete, its was a lot easier than I expected, was a bit daunting looking at that nest of wiring at first but I think it turned out nice and took shape quickly.

I used velcro to mount the esc to the computer, that way if it gives me problems, I will just remove the knock sensor and esc completely, nice an easy to remove and no holes to patch up.

I need to weld in the O2 sensor bung yet, I also decided its probably best to buy a new O2 sensor. Since I have dual exhaust, which exhaust should I put the O2 sensor in, the front or back or does it not matter?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/15/09 05:36 PM

I though I had got lucky and got the stuff to change the gm 250 distributor over to computer control and keep it all in the distributor but it didn't turn out as I expected. I pickup up the ignition control module and such out of a mid 80's v6 car, and even test fitted it in another 250 distributor in the yard, but when I got back home, I tried installing it in my distributor but the two screws that hold the module down were about 1/4" further apart. When I go back to the yard Im going to try the ignition module in the dist. that I test fitted it in to see if maybe they changed it at some point as I thought the mounting holes lined up. Here is what I picked up.
http://i175.photobucket.com/albums/w124/rockfan1815/TBI%20CONVERSION/100_0775.jpg

For now I'm just going to mount the ignition module on the passenger side inner fender and run the wires over to the distributor like the guy did on the bustedjeep.com junkyard tbi conversion that was posted earlier.
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 03/16/09 06:21 PM

Chris, You're making so much progress a little setback is expected. This may help, I don't know. GM HEI & MS
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/16/09 06:37 PM

yeah Ive been hitting a few snags along the way. I found out today the new thermostat housing I got has a larger opening for the hose to the radiator. I have an idea of how to make this work, hopefully my thinking is correct.

I got a bit done to the distributor today, removed the mechanical advance parts (springs and weights) and tach welded the arms so they dont move. I also removed the vacuum advance and secured that down so it will not move. Im going to turn the engine over till its at tdc of the compression stroke on cylinder 1 and install the distributor and then make the wires to the ignition module. Im taking lots of pictures of this process.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/16/09 06:40 PM

Also because this ignition module use to be inside the distributor and was grounded through the metal plate on the bottom of the ign module to the dist. when I bolted it down to the inner fender I put a ring terminal on it and ran the ground wire to the engine block where I have all my other ground wires going to. Picture to show what I mean later.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 03/16/09 10:40 PM

Chris

You might want to mount the HEI module on a piece of 1/8" thick alum say 2"x2" with some heatshink compound under the module... then bolt that to the fender.. or at least use heatsink compound under the module and ensure you have full contact between the HEI base and the fender surface. Hot spots can cause issues.

Keep a spare module in the glove box just in case while your shaking the bugs out.
Posted by: Titen

Re: tossing around the idea of efi for my 235 - 03/17/09 08:30 AM

If you are saying the thermostat housing uses a larger size hose than the radiator, many vehicles are like this. Just go to the auto parts and get the appropriate hose.

Tim
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/17/09 06:54 PM

I will check my local parts store to see if they have what I need.

I'll see if I have any aluminum plate to make a heat sink for the ignition module, if not I will just try using the heat sink compound. Hopefully with it being out in the open it will keep cool. Id still really like to get everything mounted inside the distributor.


So I guess it does not matter after what header flange I install the 02 sensor in?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/17/09 07:05 PM

Oh and pictures coming soon.... Got the distributor done today, as well as a few more wires terminated. My college class was canceled this evening so I got alot more closer to being done that I had expected. My new fuel pump will be here tomorrow, I hope to have the fuel system installed this coming weekend. I have no class tomorrow so I plan to hopefully get all the remaining wiring done.


Im getting anxious and nervous as I get closer to turning the key, its the same feeling all over again from when I fired it up with the 4bbl carb.
Posted by: leaded

Re: tossing around the idea of efi for my 235 - 03/18/09 06:21 AM

TBI injected GM sixes, is it somebody who could give response on the function?
does the milage got lower? more torque, and power? Is it stabile, or lot of troubles with electric failures?
Lot of guys writes about the TBI convertion, but difficult to find querys about function on the use....

Did rework a TBI 4.3 to my inline, not mounted, wonders about trouble on the road, if something happends, youre stuck! with carbs you could trick it to reach garage,etc....
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/18/09 07:52 AM

Speaking from experience with other computerized fuel injection vehicles, Id say its very reliable. Certainly there will be some bugs to work out when adapting a setup from one vehicle to another, but even then I think there should be no problem as long as you do some homework and match some specs up. The way I think of it with adapting this 4.3L tbi setup to my 3.9L 235, how would the computer know that its not on its original home? Some of the input from the sensors might not be where they usually are at some times, but the computer, to some effect can adjust the outputs to change that. Of coarse if the computer has to start making huge changes to the outputs to where its getting to far from its comfort zone, it might throw a trouble code.

And also the thing with these computers, besides them (the earlier versions at least) being very basic, is if there is a problem, the computer will go into limp mode and using preset variables should work enough to get you home or to a garage. I would say sensors barely, if ever fail. The wiring can be a problem as the harness ages, and the problem is usually right at the connector as the wire gets brittle and breaks from vibrations and the connectors get corroded from not being completely sealed. Buying a new harness instead of using one from the donor, though pricey, can help avoid these problems.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/18/09 08:13 AM

The only major thing that I can think of that would leave you stuck on the side of the road would be a fired computer, which unless something really really bad happens is also very unlikely. Ive seen a few computers that had about every error possible show up on the scan, including the main cause of all of them, the code that basically says your computer is toast, and the vehicle still started and drove fine enough to get home.
Posted by: panic

Re: tossing around the idea of efi for my 235 - 03/18/09 08:51 AM

how would the computer know that its not on its original home?

One of the problems is that the load (ohms) in the original harness is pre-set into the box (not a variable input from a sensor), as is the range of battery voltage and alternator/regulator output. There is also inductance in some vehicles from big stereos, ABS, etc.

I don't know any way to match this when wiring up an older vehicle since some of them are variable.
Most work very well, but the odd exception (including non year-correct factory parts in an original EFI car, aftermarket lamps, big stereo, alarm added) makes you wish carbs were back.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/18/09 12:15 PM

I know about the load, for the O2 sensor Im leaving that wire the original length, which worked out anyways as it doesn't need to shortened at all. The other wires werent shortened all that much to were I would think it wouldn't make a difference. No more than a foot was taken out of most of the sensor wires.

For the most part, my truck is going to be a much like a new vehicle as far as electronics and extras with power windows, door poppers, power seats, alternator conversion, a nice stereo, up to date lighting, 12 volt conversion, etc.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/20/09 10:45 AM

got my fuel pump yesturday, should have the fuel lines and all in this weekend. A few grounds left to terminate and I still need to weld in the O2 sensor bung and install the O2 sensor. Other than that the conversion is nearing complete.

To be able start and run the engine for a while I need to finish my power steering pump install, which is only measuring, buying and installing the belts.

To be able to drive it, at least around the yard (far from road legal at the moment), I have to install my disc brake kit on the front axle, buy and install my wheels and tires, and also install my firewall mounted pedal assembly, booster, m/c and combination valve and then plumb all the brake lines and bleed the air out.

Maybe after this I should finish one project before starting another.
Posted by: panic

Re: tossing around the idea of efi for my 235 - 03/20/09 10:49 AM

BTW: free benefit of having a pump in the tank is that the original fuel line may not need to be replaced with larger diameter except for really big engines.
The 45-60 positive psi increases the lbs. per minute by a huge amount, so don't regulate it down until you reach your fuel block because every line after the regulator has to be proportionate to power.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/20/09 06:37 PM

some new pictures, starting at http://s175.photobucket.com/albums/w124/...nt=100_0795.jpg

this is up to where I am at right now. Should be done, if nothing else comes, this weekend. I need to get a new ignition switch as the one I bought is a piece of crap, for some reason when the key is in run, the start terminal is powered, and then goes off when I turn the key to start. Cheap crap I bought at autozone.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/20/09 06:39 PM

oh and don't laugh at the distributor and the hot glue. It works or at least I hope it will keep the water out.
Posted by: Joe Dial I.I.#1679

Re: tossing around the idea of efi for my 235 - 03/22/09 02:25 PM

I just used the stock ECM on mine. Joe
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/22/09 02:44 PM

what did you use it on?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/23/09 10:06 AM

Just thinking of stuff to do/finish before I start her up...Is there anything I can do to fool the computer into thinking the egr valve is still plugged in, a resistor in line or something. Im just thinking that if I leave it missing and go to start it up that I will always have a engine light on and be in limp mode because the computer does not see the egr valve. Id like to be able to see if any other problems come up and see the light turn on when something pops its head out.



Just about done. Wiring is 99% complete, all that is left is the check engine light, I have the other wiring nicely coverd in wire loom. I ordered a much better igniton switch from summit, way better than the $6 piece of crap I bought locally. O2 sensor bung is welded in, picking up a new O2 sensor and a coolant temp sensor tonight. Fuel line is somewhat ran, I bent some 3/8" and 5/16" hard line for in the engine compartment, starts on the passenger side frame, up along the firewall, over to the driver side and down to the tbi unit. Supply and return lines are ran, just need to pick up some more insulated clamps to secure them to the frame. Calling lokar tonight to see about a cable end to connect my lokar throttle cable to the tbi unit.
Posted by: Joe Dial I.I.#1679

Re: tossing around the idea of efi for my 235 - 03/23/09 10:14 AM

54 GMC 302 engine.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 03/23/09 07:46 PM

Chris,

The EGR won't cause it to go into limp home mode. It might turn the check engine light on if your on the highway, I'm reasonably sure that it uses the O2 sensor to look for a change in the exhaust O2 content after it opens the EGR valve.

Use the fuel pump enable connector to pressurize the fuel system before trying to start it. Cold motor + fuel leak == low risk of fire. Also I suggest you leave the set timing connector unplugged so it starts on base timing. This separates the ign/fuel system so if you have any issues it'll be fuel only. The distributor module will fire the coil OK. The ecm only needs the dist. reference low&high signal and coolant sensor during cranking. The rest is don't care until it get into run mode.

One good thing with TBI is you can see if the injectors are spraying fuel.

Once it fired the first time even for 30 seconds or so you can plug the set timing connector together after you check your base timing. Usually somewhere around 5-10 BTDC works.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/24/09 03:22 AM

OK Thanks, I will remember that when I go to start it up.

On my 235 there is a ball bearing on the flywheel and a pointer in a opening in the bell housing. When these two line up its suppose to be at tdc or at least near it (its a on going debate on some forums). Making sure its on the right cycle, I spun the crank until these two lined up. As long as its not 180deg out, it should be close enough to start. Do it adjust it to where it idles smooth or will the computer do that.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/26/09 07:31 PM

OK I'm getting there

Fuel lines are done, definitely one of the more time consuming "to do" items for the conversion. Some pictures
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0873.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0871.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0868.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0869.jpg

I ordered some heat tape to wrap the fuel lines that go over the intake and exhaust manifolds. I may also put some type of shield that if any fuel does start to leak, it will go away from the manifolds.

the O2 sensor
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0862.jpg

and the finished wiring
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0855.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0854.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0853.jpg
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0852.jpg

For the most part the conversion is done. Before I start it I have a few more things I need to finish. I need to weld in some exhaust flex pipes in after the header flanges.
http://i175.photobucket.com/albums/w124/rockfan1815/100_0867.jpg (like my model 1952 chevy pickup)

I need to install my new ignition switch and I also ordered two magnaflow mufflers that Id like to install as soon as I get them.

I bought a piston stop so I can put timing marks on the crank pulley instead of using the flywheel and bell housing method for initial timing. I also need to get the belts so I will be able to run it for a bit longer than a few minutes.

Other than those its just about done.
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 03/26/09 07:50 PM

Chris, Great pictures and progress! You are really making it happen! I'm still locked into the laptop war. I'm finally on line with it and just got the Megatune stuff down loaded. Good luck!! Tom
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/29/09 02:13 PM

Thanks



Well I ran into bit of a problem, I wanted to purge the fuel lines to make sure I didn't have any leaks before I started it up for the first time. So I hooked up a wire (with a 20amp fuse) to the positive post on the battery and connected the other end to the positive wire on the fuel pump and.................NOTHING...well almost, the pump makes a click, more like a clank and that is it. I unhooked the rubber fuel line where it connects to the line I have on the firewall and tired it again and once again all I got was a clank noise.

I believe this is a solenoid type pump. It will continue to make a clanking noise each time I apply power, but thats it. Guess I will have to call carter up and see what they say.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 03/29/09 03:10 PM

Chris

Do you have a good ground for the pump.. ? Run a 12ga wire to the block for the fuel pump gnd. Then try the pump again.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/29/09 05:24 PM

OK I was going to wait until tomorrow to figure this out but just couldn't sit still.....

I tried a few things and nothing worked so I removed the pump completely thinking I was going to have to send it back. I said what the hell and decided to see what would happen if I connected it directly to another 12v battery I had in the garage and it came to life. That had me stumped. I reinstalled the pump with a few changes to the plumbing and will wait till tomorrow to finish and try it again. I need to resolder the power wire to the pump wire. I am going to put a better (lack of a better word) ground strap from the bell housing to the frame rail. Originally I had tested for continuity from the frame rail to the battery and it seemed fine, but I didn't really have a ground strap to the frame rail at the moment (it was in the plans). Before I try again tomorrow I am going to put a 8 gauge ground strap from the bell housing (where the battery ground connects to) to the frame rail. Hopefully that is what the problem is.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/29/09 05:33 PM

anyways, hopefully (as long as I solve my pump problem) I plan to start her up no later than next weekend.

I made some last minute exhaust mods, welded in some flex joints and ordered 2 magnaflow mufflers that will be here tomorrow. I also got some heat tape so I can wrap the fuel lines that run over the intake and exhaust manifolds.



A question on the aldl connector. What wires are required to talk to the ecm with a laptop/tuner. Just the two wires that go directly to the computer? Currently I have the ground wire, the two data wires and the fuel pump test wire. There is a wire that is connected to the check engine light wire from the computer, is that required?

thanks
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 03/31/09 04:23 PM

Took some 8 gauge wire that I had, soldered some copper 5/16" and 3/8" lugs on and installed them from the bell housing to the right and left frame rails, put power to the fuel pump and it came to life. I had the fuel line disconnected where it connects to the hard line I have on the firewall, and emptying into a gas can. Reconnected it and checked for fuel leaks. All was good.

Currently painting the mufflers I got, once I install them and wire in a switched accessory relay so I don't fry another ignition switch and also wrap the fuel lines with heat tape where they pass over the exhaust and intake manifolds, and I should be ready to start her up (fingers crossed).

Also going to load the tuner program on my laptop and change the setting for the egr.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/05/09 01:43 PM


ITS ALIVE, ITS ALIVE

Working on uploading a video of it running, will post it when its finished. Currently it idles a bit high at around 900 or so. Not sure how to correct this???

Otherwise seems to run very nice. Starts up instantly and idles quite smooth.
Posted by: Nexxussian

Re: tossing around the idea of efi for my 235 - 04/05/09 03:23 PM

Cool.

Which throttle body(s) did you wind up with?

Are you using an electronic idle air control of some kind?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/05/09 06:05 PM

presenting the video http://www.youtube.com/watch?v=XxuSGXqGnf0

I used a throttle body injection unit off of a 4.3L v6. It has a idle air control valve built in.
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 04/05/09 07:49 PM

Chris, Good going! You should have looked into the camera so we could see the big smile on your face. Does it feel like it will be drivable? What tuning will you be able to do? That is great! You are an inspiration!
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 04/05/09 09:52 PM

Well done! Sounds like the tune is close.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/06/09 03:22 AM

thanks for the compliments guys.....believe me I was jumping high and smiling ear to ear when I got it to start. For the past few weeks I was nervous about how it would run, not sure if this was a good idea or not. Of coarse there is more as I probably won't find out about any problems until I run it a few times and get it up to temp, but Im ready for anything it throws at me.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/06/09 03:25 AM

Im looking at about 3 weeks at the high end, till Im able to drive it. Installing my disc brake kit today then comes the lines.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/06/09 07:15 PM

 Originally Posted By: efi-diy
Well done! Sounds like the tune is close.


thanks, and another thanks for all your advice (not just to you but to everyone that added something as well)

Im putting together a tech tip that will be hosted on the stovebolt site and plan to have a list of all the sites I went to when planning out the conversion. Would you have a problem with me putting a link to your site?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/08/09 03:42 PM

I worked on it a bit more today. Working out the bugs that come with doing something like this.

I believe its getting a bit more fuel than needed. It starts up nice, runs nice, revs nice but when I let it idle for a long period it starts to struggle. Nice thing about fuel injection is that it won't let the engine die. I took the air cleaner off and from the top you can watch the idle air control valve (IAC) coming to save the day. When the engine starts to see it struggle, it opens up the IAC and the rpms pick back up, then repeats and it continues to do this unitl I shut it off or rev it. Revs fine even when its doing this. Took the spark plugs out and they seem a bit wet, not horribly, but wet. The spark plugs are black, mostly because of the 4bbl. This week I'm going back to the u-pull-it yard and will pickup a 2.8L injector unit to see if it corrects the problem.

Also have to get a can of starter fluid to see if there are any vacuum leaks around the adapter plate I made to mount the TBI unit.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/08/09 05:01 PM

OK, have a question. Can't quite tell from just watching, but I was wondering if the computer fires both injectors at the same time or one after the other or ???

I was thinking, what would happen if I unplugged one of the injectors? I still plan to try the 2.8 injectors, won't get to the yard until saturday though.

Anything else I should try from the 2.8?


Edit: did a bit of researching and comparing of my wiring diagram to a 2.8L V6 diagram from a 88-92 s10 and the wiring is the same, so when I go to the yard for the injector unit, I am also going to pickup a 2.8L computer.

This leads me to my next question, do I also need a 02 sensor from a 2.8 or will the one I have work and what about the map sensor, grab one too?
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 04/08/09 08:58 PM

Chris,

Depending on the calibration the injectors could fire alternating or together.

You can try unplugging 1 injector - it may be lean. Get the calpak from the 2.8.

Everything else is the same.

For tuning it would be a real good idea to buy a wideband 02 sensor so you know which way you are going.

Just as an aside - this is where tuning the GM ecm gets awkward - no data logging capacity.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/09/09 03:25 AM

thanks

Does the calpak have to come from the same model ecm (1227747). The 2.8l's from 88-92 had a different model # ecm (1228062) wiring is the same though.

http://chevythunder.com/gm_throttle_body_injection_pg_1.htm
looking at the ecm list, maybe I should also look for a 3.1L not sure what truck that came in.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/09/09 06:25 PM

Ok did some more researching and thinking. The 3.1L which uses the same 2bbl tbi220 unit came in the 91-93 chevy lumina, 89-92 olds silhouette and 91-93 pontiac trans-sport. The wiring, like the 2.8 is also the same as the 4.3

I may buy at the yard 1 2.8 injector unit/pod, 1 2.8 computer, 1 3.1 injector pod and 1 3.1 computer and do some mixing and matching. A nice thing about the 3.1 computer is that it has a trigger wire for a cooling fan relay. Not sure if I should also get the 2.8 computer or not. The yard charges about $20 for computers. 3.1 is probably a bit closer than the 2.8 and the fan relay trigger is a plus.

I can try a few different combinations
4.3 computer with 2.8 injector pod
4.3 computer with 3.1 injector pod
3.1 computer with 3.1 injector pod
3.1 computer with 2.8 injector pod
3.1 computer with 4.3 injector pod
2.8 computer with 2.8 injector pod
2.8 computer with 3.1 injector pod
2.8 computer with 4.3 injector pod

anyone know or can get the specs on the 2.8, 3.1 and 4.3 injectors

not sure what sensors and that will interchange, I imagine the IAC, TPS and CTS won't make a difference, MAP might need to be changed and MAYBE??? the O2 sensor.

I also read somewhere that the vac port on the MAP must be pointing down. TRUE?
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 04/09/09 11:22 PM

http://www.diy-efi.org/gmecm/component_info/tbi_injectors.html

ALL the sensors are common - no need to change any of them if you keep the same TBI housing. There are 2 different TPS connectors and they don't interchange. The entire calibration differences are in the cal pacs.

Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/10/09 03:19 AM

Thanks

from what I understand the calpacs from a 2.8 or 3.1 can not be installed in the 747 ecm as that ecm was only for 4.3L and up. Otherwise the ecms though different #'s, wiring wise are the same.

Yeah I am keeping the same TBI housing, just taking the injector assembly on top.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/11/09 11:43 AM

Its getting better!

Picked up a 3.1L V6 Injector unit, cleaned it up, put it on and started her up. The struggle is less frequent then it was with the 4.3L injectors. It seems like every 4 minutes it will bog down and rev up a bit and then be fine then repeats after a while. IAC doesn't have to save it as much. I didn't want to buy more than needed so I found a good 3.1 computer and 2.8 injector and stashed them for later. Looks like when I go back I will grab the computer and 2.8 injector unit.

I would really like to use the 3.1 computer if possible because of the cooling fan trigger.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/11/09 12:05 PM

What would be needed or what do I have to do to NOT have the computer control the timing. It seems to run better when the connector you unplug to set the base timing is left unplugged. I would either switch back to the HEI distributor or a stock distributor with a pertonix (sp?) unit and just have the timing controlled by vacuum.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 04/11/09 12:09 PM

Where do you have the base timing set?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/11/09 01:16 PM

well Ive been trying it in a few different spots. originally had the pointer on the bell housing lined up with the ball bearing on the flywheel.
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 04/11/09 02:11 PM

Any way to degree the damper for 0*,10* & 20* BTDC. Without knowing where the base timing is will make tuning a real bear.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/11/09 02:20 PM

I bought a piston stop, but someone said it won't really help on a engine without a keyless crank pulley?
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/11/09 02:21 PM

what should the base timing be. 0 TDC?
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 04/12/09 11:18 AM

Starting point for the base timing is what ever GM used for the ECM donor. Try 0 or 10*BTDC
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 04/12/09 11:26 AM

Well the damper won't rotate on the crank once it tight otherwise you can drive your alternator with it. Measure the circumference and divide that number by 360. Write it down. That is inches/degree. Set up a reference pointer and using your piston stop mark the 2 lines on the damper. Measure the radial distance between them. Take that number/the inches per degree number. That is how many degrees between the 2 mark. Measure 1/2 way this is 0 deg. (at least until the damper is removed or the crank bolt lossened) Now calculate the distance for 10&20 deg and mark it on the damper to get 3 timing marks -20,-10 &0.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/12/09 02:31 PM

thanks sounds easy enough, now I just need the time. Going to be working about 14 hours overtime (40 normal) for the next couple of weeks. 1 weeks overtime will more than pay for the MS system when I turn to that to control the fuel injection. Before I do I just want to try a few things yet.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/13/09 03:18 PM

Set the timing to zero (pointer and ball bearing on flywheel match up)

Installed the 3.1L computer and left in the 3.1L injectors. Let it idle until it got up to around 190 degrees and actually did better than I expected. Has a slight fluctuating idle but not bad. Idles around 800. The next time I have a chance Im going to experiment a bit more. Plan is to try both the 4.3 and 2.8 injectors with the 3.1 computer and see how it goes. Still wondering about the 261 running better with a 4.3 computer and 5.0 injectors. Maybe I will have the same outcome with the 3.1 computer and 4.3 injectors.

The Throttle position sensor checks out fine, the map sensor I'm not quite sure on. I get 5.1 volts across terminals A (sensor return/ground) and C (sensor 5v reference), which seems correct. Across terminals A and B (sensor signal to computer) I get like 4.2 volts. Across terminals C and B I get about .3 volts. All this is with the key ON and engine OFF. From the testing procedure that I got off of a automotive repair site, this is backwards.

I have to test the IAC valve yet.

More than likely I will just end up purchasing a new MAP sensor anyways and getting a few IAC valves at the local yard.

will see!!!
Posted by: efi-diy

Re: tossing around the idea of efi for my 235 - 04/13/09 06:09 PM

MAP sensor is fine. Your not at sea level so the sensor is reading absolute pressure. If you get a GM shop manual it'll give the voltage vs kPA. Start the engine and measure MAP out to gnd.

If you had a wideband O2 you would be able to sort out whats going on fuel wise. Also try advancing the base timing a bit say 5* btdc.

I'd say your not far off but tuning by swapping parts is really a coarse method and may not get you to the desired end result.

Try enriching the mixture using a propane touch (un-light of coarse :)) and flow some propane done the TB if the rpm increase your lean.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/14/09 05:41 AM

thanks again

I was corrected on the stovebolt site, when the pointer and the ball bearing on the flywheel line up it is not 0 deg TDC, its actually 10 BTDC.

Since I will need a wideband O2 sensor if/when I go to MS, Im going to get one now anyways.

I will try the propane as well. Unlit of coarse.
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 04/14/09 08:41 AM

I got a smoking deal on an Innovate wide band kit on eBay. Sensor,controller, gauge, & CD for about 1/2 price.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 04/14/09 10:11 AM

thanks I will see what ebay has to offer.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 09/24/10 06:12 PM

A bit of a update on this. I have not given up on this, I just recently in the last 3 months started working on my truck again after taking a break for about a year it seems. Othe hobbies took over, almost to the point of complete lost of interest in the truck and going as far as listing the truck for sale. After I listed it for sale I started working on it and decided to keep at it.

When I stopped, I had the 3.1L computer, a 4.3L throttle body unit and injectors and was quite happy with how it ran. Truck never seen pavement yet so I can't say much more about that. At startup the truck idled ok, started with a bit of a high idle (about 1000rpm) and as normal would start to drop the idle to about 700rpm. Problem was when the idle dropped and the computer started to lean it out at idle the computer would have to give it a bit of a jult (Idle air valve would open and idle would increase slightly) to keep going.

Just recently I picked up a few things to try out. I grabbed a TBI unit off of a 3.1L at the local u-pull-it yard. The 3.1L TBI unit has smaller throttle openings then the 4.3L (1-3/8" compared to 1-11/16") and also a lower flow rating for the injectors (33lb/hr to 40lb/hr).

First I tried the 3.1L computer with the 3.1L TBI unit and 3.1 injectors. Result - would not idle at all. Started fine but if throttle left unattended it would die instantly. Guess is too lean of a mixture.

Then I tried the 4.3L computer with the 3.1L TBI and 3.1L injectors. Result - same as above but not as bad, but still would not idle. Probably because the 4.3L computer has a longer injecter pulse width then the 3.1L computer so it wasn't as lean.

Next I left the 4.3L computer hooked up, but instead used the 4.3L injectors on the 3.1L TBI. Result - much much better, idles very nice, starts at 900rpm and as the engine warms up and the computer starts to lower the idle rpm and lean out the fuel it goes down to about 650rpm.

This time around I'm getting technical. Using a ALDL to usb cable and diagnostics program called WinALDL loaded on my laptop so I can monitor the computer and see whats going on. From reading different forums online about tuning I know I can find out if I'm running lean or rich by monitoring the BLM table, a number above 128 means the O2 is seeing a lean mixture and below 128 its seeing a rich mixture.

I've also come to realize that the stock computers tune just isn't going to do. So from doing some research on thridgen.org (camaro forum), they have a few computer tuning forums. http://www.thirdgen.org/techboard/diy-prom/ & http://www.thirdgen.org/techboard/dfi-ecm/ I found a few options for tuning. First option (which is what I'm going with) is an adapter from moates.net, since the eprom thats used in the earlier GM computers require expensive equipment write to, this company has came up with an adapter to use a later flashable chip. A little solder work is required but for $135 for all thats required its probably the cheapest option out there. Parts needed:
http://www.moates.net/g2-memory-adapter-060-leg-spacing-p-36.html?cPath=64 - adapter gets soldered onto the board after the old 24 pin socket is removed
http://www.moates.net/s2-aries-28pin-zif-socket-p-44.html - 28 pin socket
http://www.moates.net/c2-sst-27sf512-chip-p-39.html - new flashable chip
http://www.moates.net/burn2-chip-programmer-p-197.html?cPath=64 - used to burn or write the program to the new chip

The other option, also requires a bit of soldering is the EBL flash.
http://www.dynamicefi.com/EBL_Flash.php
It replaces the part of the GM ecm where the eprom or memcal and calpak reside with a new board that allows you to flash a new program through a serial data cable, so no need to remove the chip to program. Also includes datalogging and the way I read it the ability to have multiple tunes that you can switch back and forth using the software or a switch. This option was a bit more at $350. I liked this the most but wanted to keep this project as low cost as possible. I have not read any negatives with either route so I shouldn't have a problem.

I also came across a program that will take a saved datalog file from WinALDL and make the changes to the bin file(ecm file that is burned/written to the eprom/chip) for you. That program is called ALDL to BIN

On top of that I am using another program called TunerCATS to edit the bin file to disable the egr valve and maybe a few others. I can also use this program to burn/write the new bin file to the chip.

To also help I purchased a Innovate Motorsports LC-1 wideband O2 sensor kit so I can monitor the air/fuel ratio more closely.





The thing I need to figure out is what TBI unit would be better. I'm thinking I should switch back to the 4.3L TBI unit so everything matches. 4.3L computer, TBI unit and injectors then start tuning. When I open the throttle when using the 3.1L TBI unit just the sound of the air rushing in sounds restrictive.

I'm going to post a picture soon and ask were would be best to mount the O2 sensor. Im not certain the location I have it at now is the best place for it. And I may end up changing the narrowband O2 sensor to a heated version. I don't know if its OK to always run using the LC-1 wideband kit.
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 09/24/10 06:46 PM

This is currently where I have the narrowband O2 sensor. Just a stock GM replacement that goes to the ecu.
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0862.jpg

I was wondering if it would be better to mount it closer to the header or in the header at the collector.
http://i175.photobucket.com/albums/w124/rockfan1815/engine/100_0094.jpg
Posted by: drummin52

Re: tossing around the idea of efi for my 235 - 09/25/10 04:34 PM

Anyone have a part number or a car I can use a heated O2 sensor from.

Thanks
Posted by: Beater of the Pack

Re: tossing around the idea of efi for my 235 - 11/18/12 09:04 PM

BTT