89 TA engine problems, help please
 

The car is a 89 TA. It has a 307 Tuned Port V-8. The car, when cold, runs find. After a few, the car starts to act up. It lacks power, and surges during cruise. When you accelerate from cruise, it hesitates. It is running very rich. While driving, it is not getting a check engine light. It will stall out when you come to a stop. A scan was done a few days ago, and it came up with a faulty MAF sensor. That was replaced, but it did not help anything.

To me it seems like a O2 sensor. It should be regulating fuel, but is not. But there is not a check engine light.

I am out of ideas, anyone have any?

I'd check it with a scanner first. Not to read any trouble codes but to see what the computer sees in terms of sensor inputs. Things like coolant temp, MAF voltage, Injector pulse, etc..

I'd check to make sure that the fresh air intake hose didn't have a crack/tear in it that allowed unmetered air into the engine without passing throught the MAF.

Possible fuel pressure test.

Unfortunately, this kind of thing is so hard to fix without being there, tools in hand.

SGT..eliminate the obvious first, intake air leaks, clean throttle body & IAC valve, all ECM grounds clean and tight, base timing...If scanner indicates way rich condition and no codes stored you probably have a bad ecm. Factory ecm part #1227727 and 12276360 were notorious...if I remember the part #s after close to 20yrs theres a problem!!!!!!!!!!!!
"mean"
and glad to be back!!!!!!!!!!!!!

It could be anything I bet its one or more 02 sensors.

I had an 89 camaro 5.7 tuned tort doing the same thing. Check the resistance of each of the injectors. One bad injector on each bank will screw up the way it runs once it goes into closed loop.