Hi, I am new to this,, I have a 1990 trans am gta 305 tpi engine runs great when I first start it, then once it warms up starts to run rough has a miss, backfires and if it stalls sometimes wont start agin for a least a hour, but if I spray quick start it starts but runs rough,, please help... map is etc.. just new at this but would like to get it back up and runing right.

oh has new plugs dist.

thank you in advance

 

bump, sounds like same problem a lot of us have on 3rd gen Check out this link. A lot to read but worth it. Good luck
https://www.thirdgen.org/forums/tpi/...arding.html3rd

 

You need a fuel pressure gauge.

 

That link didn't work for me, try this one https://www.thirdgen.org/forums/tpi/...regarding.html

 

but if thats the problem would it backfire though the muffer, when releaseing the gas petal? and it would not start when it run for only 5mins or so,, then I would have to wait at least 1 hr or more before it started again,,where I live right now its not that hot out its low is 4c and highs of maybe 12c,, I am confused some people tell me its the injectiors or vacuum leak..what do you guys think,,?

 

In that 5 minutes it runs, the engine warms and your ecm switches from open, to closed loop. In closed loop mode, the ecm starts interpreting data from sensors and making adjustments as needed to run the engine.

Lack of fuel sounds to be your root problem. Once in closed loop, the ecm is either getting skewed data from a faulty sensor reading or the fuel pump is unable to keep up.

The reason it takes a hour to refire, the engine needs to cool to the point that the ecm is back in closed loop mode.

Do this:
1. Test fuel pressure both when running and when it begins to misfire and won't restart.
2. Check ECT.
3. Check oxygen sensors.

Let us know what you find. And if needed, we'll go from there.

 

thanks will try that

 

Come up with anything?

 

havent been able to do anything yet wedding, thanksgiving etc... will let you know when I do,,
but just to let you know I smell fuel in the exhast when it is running,,,and it runs great when first start, then it goes rough as it gets warmed up or the ecm takes over,,and within about 1/2 hour it will die, and wont start for at least 1 and 1/2 to 2hour hours.. could it be the module, or pickup corl ?

 

Im having very similar problems. Did you find a fix?? Any help would be awesome. Im getting frustrated with this car! (86 TPI)