Ok, we're on the road... Exhaust attached, 12V run from fuse box to choke. Starts beautifully, no black smoke out the back, no gassy smell when done running.
Now for the bad news, the backfiring is worse than ever. I got some in the driveway with the filter off and tall flames coming up. It seems to come and go, get worse when it's hot. The temp light came on after coming up the big hill and sitting at the light on top. I need a shorter spring for throttle return so it doesn't go quite to full idle sometimes.
When you give it small throttle, it backfires, sputters and a few times stalled. When it does backfire, it misses really badly and takes a while to clear up. Once cleared up, the backfires are gone for a while.
It ran fine in the driveway for my testing. Of course, but I think that's just due to cooling down. :-)
I checked the vacuum in different spots. 20 lbs steady at idle from the manifold. I connected to the hose that normally is attached to the vacuum advance, steady, but I think lbs lower as expected. When reconnected, you can see the vacuum advance kick in and the RPMs go up. The transmission is connected to the upper vacuum off the carb, 0 lbs at idle, but you get vacuum when the throttle is open.
It's either fire or valves. Reading through posts on Camaro website, it could be condenser or something else. Murphy says it's the valves. No time yet today to look at it.
Here's a simple summary: When it gets hot, it backfires on modest acceleration. After the backfires, the car misses terribly and clears up after 3-5 seconds.
(sinking feeling) Yeah, I know, it's a problem with the valves. Before I bought the car, it had a lot of quality garage time with little running. I replaced the fuel pump and it's got good gas. But heat could also point to an electrical issue. It just seems odd that it would clear up over time...
Questions:
1) Is this OK for the transmission to only get vacuum when the throttle is opened up part way? Should I tap into the dist advance and plug this vacuum?
2) Experience with HEI distributors Langdon's sells? Big advantage to the mini or the round coil outside aesthetics? I was going to put one of these on anyway, might just do it now to cut one more problem out of the equation.
Thanks!
Mark
