n00b question here. Just bought my truck a few days ago and I'm working on getting it all dialed in.

I have looked up the firing order of a '66 292 as 1-5-3-6-2-4. Checked several sources to confirm this. The funny thing is, it is now firing 1-5-3-4-2-6. While it runs a little rough, sounds like the valves are a bit out, smells like it's running rich, etc. most of which I attribute to the fact that it's been sitting for a while and I expected, I can't figure out why it runs reasonably well in this order and not well at all in the proper order.

Is there any obvious answer I'm missing here, is my engine a fluke, or any other info/ideas?

Thanks

You may have a problem that the wrong firing order is able to hide. Have you done a compression test on it? adjusted the valves?

Not yet, but I was thinking the same thing. Any tips / links for how to adjust valves? And what range / variation in pressure should I look for?

Thanks again

A shop manual for your truck would be a good thing to have. Otherwise, any Chilton or Motors manual that covers 1966 will have the specs in it and most mechanical repair info as well.
When doing a comp. test, pull all of the plugs, not just one at a time. If the compression is within 5 psi of each other, you probably don't have a problem. Valve adjustment is dependant on whether its solid or hydraulic lifters. I don't have the specs in front of me right now.

All chevy sixes, and for that matter all inline sixes that I am aware of, have a firing order of 1-5-3-6-2-4. Switch the wires on 4 and 6 and see if that doesn't fix your problem.

Tim

Most 6's and 8's I have ever worked on have a pair of cylinders you can swap without too much degradation of the idle. It doesn't usually show up till you try to drive it and don't have any power. So, how does it drive?

Thanks for all the info so far.

gearhead - on first attempt at a parts store, they did not have the proper manual, but so far I have found the specs I need on the net. I'll start with the comp test and go from there. I have a mechanic in mind if I need help with the valves. If I remember correctly from my last '66, the lash needs to be adjusted while idling. These are solid lifters, I believe?

Titen - I did that and that's what has me confuzzled. It runs a little rough with poor acceleration in the wrong order and terribly / barely at all / backfiring in the correct order. It actually ran reasonably well (somewhat noisily, like it needed a valve adjustment) when I brought it home, but the first thing I did (other that cleaning up some gunk under the hood) was clean and gap the plugs, and then poured some water down the carb while running to clean (a friend showed me this tip, but may be a bad idea - any info would help here as well.)

Nexxussian - as I stated above, it ran reasonable well (in the wrong order) until I got it home and started tinkering. Now it runs worse in the wrong order (idles not too bad, but poor acceleration), and barely at all in the proper order.

Also, just occurred to me that I cleaned up the ignition wires, and possibly damaged one or more, so I may try pulling one at a time to check for any change in idle.

Thanks again (again)

i think someone may have put the wrong distributor cap on your engine. does it have a HEI? if so they may have used a 4.3 V6 cap. i think they are criss crossed in the cap. if so get a new proper cap. tom

Sounds like a good tune up is in order. Cap, rotor, plug wires, points... and do that compression test...

You can mail order shop manuals from most any aftermarket parts vendor that handles parts for your vintage of truck.

Have you checked the timing so far? You didn't say anything about whether the you had put a timing light on it, but if you haven't, it might be a good idea. I agree with gearhead; going through all the ignition components can't be a bad idea. And if it's been sitting for a long time, the gas has probably gone bad, and the fuel pump diaphragm may have dried out and cracked.

Problem(s) solved! Running sweeet.

Thanks again for the help / info.

Took a while to get finished up, with working, summer heat, and general laziness.

So I went through all the basic tuneup stuff, new plugs, cap, rotor, points, condenser, vac. advance (in fact replaced entire distributor since it comes with the last 3 listed components, and it looked a bit worn out). Rebuilt the carb., replaced some wiring, checked compression (all cylinders 110-120 psi, mostly towards the high end) and lastly timing.

It happened to run out of gas in my driveway before I was done, which was actually probably a good thing, since it means all the old gas is now gone.

Oh, and no HEI to answer that question. Good bit of info to file away for future reference if I ever decide to go that route. For now I just need a good truck that can get me around and help me get some work done. May get more into performance in the future.