I have a 305 in my 86 Trans Am
It is somewhat modified. it has a comp Cam, Performer intake, headers, 600 cfm carb. the engine is from a 84 camaro. the 5 spd. trans is from a 92 Z28. new clutch.

I just tuned it up before winter and now when it is cold it seems to run like it is only running on 7 cylinders till it warms up.

I don't know if it is caus of the cold weather or not. I have been told it may be my choke but I have checked it and it seems ok

I have a new cap and rotor and wires and plugs ( All Axcel).

It always starts very quick even when cold but won't run right till it is warmed up. if you try to drive it before it is warm it will bog out. Once warm it runs great.

I am going to put the old cap and rotor and plugs back it it today since it did not do this before I tuned it up and try to figure out by process of elimination what is wrong but any advice would be helpfull....

Thanks....Frank Mars....

 

i'd suspect the choke

 

Almost certainly a choke or mixture problem. The distributor cap and rotor wouldn't get better as the engine warms.

 

I have an 87 Trans Am and I have the same problem. It shoots black smoke and sounds like 7 cylinders. It upsets me. Once its warmed up it is much better. Does it do damage to the engine? How do I fix it. I've tried to check the computer but it doesnt respond or send information. How can I fix this problem?

 

I had the exact same problem and sure enough it turned out to be the choke on the carb...

 

I thought this was all carbed cars. Mine is an 84 with an edelbrock 750. Carbed cars just run crappy till they are warmed up. I have never saw one you could just fire up and it take right off just like if it were warm. Once mine warms up to about 160-180 it turns back into a beast. But when I first start it, it does the same thing yours does. I have new plugs, rotar, distributer cap, fuel filter, air filter and just cleaned the carb with cleaner. Don't feel bad.

 

I have the same problem, but I have 305 tpi.
I think tpi doesn't have choke does it?
My car sounds like 1 cylinder doesn't run in every 2-3 seconds.
Any ideas?

 

Thanks for the info, But There has to be a soloution, Your car and my car certaintly did not run bad till they warmed up when they were new. Also my car ran fine last winter. I am going to keep checking stuff. It has to be something small I have overlooked.
I will let you know If I fine it. No car should take 20 minutes to warm up, Hotrod or not....Frank Mars....

 

My car does it too...
But hot, it's still has a little stumble, been told that a worn cam can do that...
Anyway if your using an open element THATS the problem!
On my stock cleaner i had removed the tube that goes to the manifold, put the thing back and the car is better when cold... (otherwise it would stall).

note that i've done a tune up, wires ,plugs, air filter, fuel filter...
I checked my compression 170 on all + or - 10. I did not do leak down test since i dont burn much oil, and no antifreeze.
I did my intake gasket a while ago (i had a external oil leak, oil was making is way up an intake bolt) I wish i could test a new coil and distributor.

and me too take at least 20 min to get normal op temp

 

i can relate, edelbrock 650, blows *** trying to start it and keep it running in the cold, lots of white smoke, i KNOW my choke isn't working worth a ****. Let it warm up 5 minutes and it runs fine.