I have a 2002 Pontiac Grand Prix n/a 3800 Series II. Has approx 77,000 miles on it. I've owned it the past year and a half and had no real issues with it.
I traveled out of state, 4+ hours from home to visit family. Car has been fine until Tuesday when we went to leave. We drove about 25 mins and stopped for a quick dinner. Tried to restart and it wouldn't start without giving it lots of throttle and it running overly rich. Black smoke from tail pipes. Had it towed back to the house to look at it Wednesday morning. It fired up and ran perfect in the morning. I drove it to a gas station filled up and then back to the house with no problems. Loaded everyone back in the car and the same issue. Hard start, have to hold the throttle running rich until it just won't stay running at all. Symptoms get progressively worse.
We cleaned out the IAC which seemed to help, but the engine had cooled at this point. Get ready to leave and same issue.
It starts and runs fine when cold, but once turned off after warm up it doesn't want to run.
We replaced the Crank Position Sensor after searching the forums here, along with the Ignition Control Module. No change. No codes have been set. We scanned it with a basic hand held and the TPS shows like it's working, the ECT reads normal. There was possibly an issue with no reading from STFT on one of the O2 sensors but the car may not have been running long enough to enter closed loop.
The only other symptoms are the PCM doesn't seem to be setting codes at all. We unplugged the EGR and the MAF to see if that changed symptoms and no codes were set.
Also the air motor, in the aircleaner box seems to be sticking and blowing the underhood fuse.
We are now thinking that possibly this is supposed to help cool the PCM and isn't and the PCM itself is failing.
Any help would be greatly appreciated as I am using up vacation days and need to get home ASAP. I am supposed to be moving this weekend. Thanks.