Well if for any details of what I have already checked you can go here http://www.thirdgen.org/techbb2/show...hreadid=159455 but here is an overview:

I just got my 350 all put together and in the car along with new exhaust and headers, xe268 cam, ported 416 305 heads and maybe a couple of other minor things. Anyway, when I started it up the #7 primary got red hot. The #1 looked pretty hot but not red. The rest seemed to be decent but maybe a little hotter than they should have been. Anyway, I think it may be related to my timing somehow. I had my cousin reset the valve lash because this was the first time I had done it on my own and after he did it it still did the same thing. I used a compression tester and no mater whether it was a cylinder that got hot or not they seemed to all be right about at 150. I checked and while at top dead center according to the timing tab the rotor does appear to be pointing at the right cylinder(#6 since it was the exhaust stroke for 1). I also checked the keyway on the crank to see if it was in the right spot when the timing tab said top dead(45* from top) and it appeared to be pretty much exact for all I could tell. The reason I think it has to be timing related somehow is because when I try to set the timing it will only run decent if it is above the timing tab(advanced?). I think that if I moved it far enough away from it it may not have even got the header so hot. When I try to adjust it down to about what it is supposed to be it backfires through the carb and dies at about 8*. The only suggestion that I have heard that I dont think is ruled out for the most part is if the timing chain is a tooth off or something but I dont know if that would cause these symptoms or not. Also was trying to make sure I had that the disributer was in the right tooth. It was as far as I could tell but cant guarantee it. Would either of these cause this problem?

Thanks

Ben

 

A few years back i put a big cam in my corvette, had the l98 motor. My headers were glowing after i took her around the block. I pumped up my fuel psi from 43.5 to 50 and it solved the problem, however, it could be the opposite, runing rich. I would pump the psi up to 50, take it around the block and see what happens. If you have a scan too30l, that will be even more helpful.

keepus posted!

 

It isn't uncommon for the ring on a harmonic balancer to slip a little. Try setting your timing by ear and if the primaries cool down, then your balancer is off. Also keep in mind since it's a CC carb and distributor, the computer could be retarding your timing. I don't remember if the old q-jet cars had knock sensors, but if so then false knock could cause this to an extent. Hope it helps...

 

Osmosis, it is carbed so it has a mechanical fuel pump and doesnt have a fuel pressure regulator.

TheGreatJ, it does have a knock sensor, but I have the computer disconected from the distributer while I am trying to set the timing. Also, I dont think it is the balancer because it is brand new. Also, I checked and the keyway on the crank was at 45 from the top when I had the timing tab lined up at 0 degrees and the rotor was pointing at #6(exhaust stroke for #1). Actually, do these things have mechanical advance? If so how much, because I was trying to set it and keep the rpms up around 2 grand to keep the cam oiled good to break in. If it has mechanical advance that could be the problem. I may need to let it idle while I set it. Let me know if this is a possibility.

Ben

 

hmm, i thought it was a tpi car. You might try advancing the timming a few deg. Just a thought.

 

Yes, I think advancing it is what it needs, but I was just trying to figure out why the timing mark was so far advanced already. Does anyone know if the computer controlled distributers had any mechanical advance?

Ben

 

No mechanical advance on computer contrlled distributors.
Hi, here's what I see.
You say that No.1 is hot too but not red.
Well that's telling me that 2-cylinders on the same side of the motor farthest from the carb, fed by the same side of the carb(assuming dual-plane intake) are HOT(AKA=lean).
Timing will uniformly affect all cylinders, fuel will be more extreme the farther from the carb. I would say try another carb or richen the mixture on the side "opposite" the hot cylinders, since the drivers' side of the carb feeds the passenger side cylinders and vise-versa.

 

OK, that kind of makes sense. I dont have access to another one of these carbs though. This is the second one I have had on it because the other wouldnt run worth crap. Also, I know I have a timing problem because I cant get it under 8* without it backfiring out the carb and dying. So I may have a couple of problems but I don't know how to fix the one for sure. How do you adjust the fuel mixture on the primaries on these carbs?

Ben