Pontiac Repair: 1999 Pontiac GT 3.8L seriesII, mass air flow sensor, mass air flow

Question
The engine starts and runs well when cold.  After going for a short trip of about 5 mi. it will restart but die immediately. I can keep it running by keeping pressure on the gas pedal but as soon as I take my foot off the gas it dies immediately again. I was able to get home by restarting it about 15 times and keeping pressure on the gas pedal. While it was running it ran smoothly. After running like this for 5-10 min. it begins to run very erratically with lots of dark smoke. The check engine light does NOT come on ,it is not burned out I checked. The TRAC OFF light does come on and stay on.
The Pontiac garage told me, after analyzing it, I needed 2 coil packs and new spark plug wires. I replaced them but had no improvement! Pontiac told me they couldn't check the ECM because the engine was running badly.
What should I do or check next?
Why doesn't the check engine light come on?

Answer
Hi Chris:

good question. If the car is running that badly the service engine lamp should come on. It doesn't matter how bad it's running you should be able to look at the engine data with a scan tool and see what is going on with it.. It would try this unplug the mass air flow sensor it's on the top of the throttle body it has 3 wires going to it I think they are black,yellow,pink, and start the car up and see how it runs. The service engine lamp will come on and if it runs better you found the problem. It will hesitate but see if the billowing black smoke stops and it smoothes out. The other thing to check is with it running take the vacuum hose off the fuel pressure regulator and see if ther is raw fuel in the vacuum line if so the regulator is bad and that could cause it to run bad and spew black smoke as well. Good luck :)