I have a 1990 Pontiac Trans Am GTA, with the 350 cu. in. (5.7 liter) Tuned Port Injected V8 engine. The car has some problems with idling too fast, or too slow, and sometimes, the engine cuts out. I was told that one of the things to check is the "mass air flow sensor".

I would like to know if this car has a "mass air flow sensor", and if so, where is it located?

Thanks in advance!

 

Actually you dont have a MAF. your system is Speed Density, it uses the TPS sensor and the MAP sensor. I have a 91, and I looked for the maf for like 20 minutes one day and got fed up and looked it up (how I found TGO) lmao.

Check and clean your TPS sensor IMO.

 

Nope. No "mass air flow sensor" on your car.

The TPS doesn't get dirty. You probably mean check the TPS and check and clean the IAC.

 

Could someone tell me where the "MAP sensor" is located?

I replaced the TPS. I don't think it requires any adjusting, does it?

I had the IAC valve replaced by a mechanic. He told me that it would take a few days of driving for the computer to "learn" that a new IAC valve had been installed.

Unfortunately, I don't think this happened. The car is still not idling right months later. I suspect that it might be the computer (ECM), but I was told that if there are NO codes showing (relating to the ECM itself), that means there is nothing wrong with the computer.

Of course, I have been told the opposite as well; that the computer can be faulty and NOT show a code.

When the engine runs, it runs very well, except for this idling problem.

I am not sure what is wrong. Any ideas?

 

https://www.thirdgen.org/tpimod2

IAC and TPS adjustment procedure from thirdgen's tech articles. Give it a shot and see what happens.

 

+1 What he said