Troubleshooting

[MiDMoTSI]

Issues with a 2001 Bonneville SE with 129k miles. I bought the car in April and since owning it I replaced a faulty fuel sensor, oil pressure sensor, several burnt out bulbs, and upgraded the stereo with another OEM from harofreak.

Up to this point, the car ran without any issues. This past week, when my daughter drove it to work, it began to run rough and died, though it immediately restarted and she was able to park it at work. When she called, my first question was how much fuel was in it and when she said it was on empty. I took 5 gallons to it but prior to adding the fuel, I checked the gauge and it was still indicated 1/8th. I refueled and took it for a test drive. I felt the surging and hard stumbling, I also lost power at 60mph, pulled over onto the shoulder and it immediately refired. Though the previous owner indicated he had it tuned last summer, I went ahead and did the following:

Changed the fuel filter - Wix
Spark plugs - NGK TR55
Wires -NAPA Belden
New PCV

At this point,I have not change any ignition coils or the ICM. Since it was getting dark, I decided to wait until the next day before cleaning the MAF. Test drove it that night and it still had a slight stumble, nothing like it was earlier. The next morning I decided to drive it to work - 5 miles, in city street driving, max speed was 35mph. At a traffic light, it died but immediately restarted. I stopped by the shop that does our vehicle fleet maintenance and we pulled the following codes:

P0131 - O2 signal low S-1/B-1
P0230 - Fuel pump control circuit problem (This code may have occured during the fuel filter replacement. After I bled the fuel pressue, I pulled the fuel pump relay and I cranked the engine a couple of times per this thread: http://www.pontiacbonnevilleclub.com/fo ... 45&t=23215)

When researching the P0131 code, possible causes pointed back to the MAF which has not been cleaned and checking that the #6 plug wire wasn't routed against the O2 sensor or wiring.

Yesterday afternoon I verified the #6 plug wire, cleaned the MAF with MAF cleaner and a Q tip, and cleaned the IAC. Test drove 5 miles, still had a slight stumble, again died at a stoplight/immediately refired, and while idling at another stoplight, the 'service engine soon' light came on. Scanned again for codes and got a P0102 - Mass or volume air flow A circuit low input.

I'll check the MAF cleaning again, the wiring and connector, and vacuum leaks this afternoon. Anything else I should check?

Sorry for the long post, I wanted to get all the information out there.

[00Beast]

See if a local junkyard will let you "test drive" a MAF and see if it does it.

[MiDMoTSI]

May have to try that, unfortunately the local salvage yard is mostly trucks and 4x4's. The next closest one is 35 miles away.

Did reclean the MAF with MAF cleaner, shines like a newly minted dime. Cleared the code. During the test drive (15 miles), it runs great the first 5-7 miles, then you feel a slight stumble. These miles were at a speed of 60-70 mph. The rest of the miles were in town city streets. Last 3 miles, died twice at intersections. Pulled a P0102 again. So one way or another, I'll have to try a MAF swap.

Every reference I can find for Pontiac or GM 3800 P0102 states a possibility of a downstream vacuum leak. Could the replacement PCV cause this? Or any other possible vacuum locations?

[MiDMoTSI]

Replaced with a new MAF. With about 50 miles, no problems.

[Ken_W]

It's amazing how many times the MAF sensor ends up being the culprit in these types of situations.

Congrats on getting it fixed!

Ken_W