Greetings all, so my sister enherited our late dad'* '92 Bonnevile SE. It'* in great shape and after she got her driver'* licence she started using it regularly. Our mom let it sit in the driveway for over a full year.

It started stalling at lights and throwing an SES last week.

I scanned with the GM tool, and got the MAF sensor (34). I performed all the regular maintenance on it today, spark plugs, oil change, fluids, cleaned the intake/throttle body. I checked the air filter and it seems ok.

The car still runs low idle but only stalled once on a 10 mile test drive I took it on, I disconnected the sensor that'* on the air filter box thinking it might be the MAF (although I suspect the maf is the rectangular black box, held in place with three screws, on right after the plastic ends on the intake, on the metallic part which I guess is the very start of the throttle body...) and after disconnecting it, the car ran better and no longer stalls.

My questions are:

Which one is the MAF sensor and how much are we looking at for a replacement.

The car has just over 150.000kms on it.

Thanks and congrates for the fantastic forum site.

The MAF is the black rectangular box. Replace it with a working one from a scrapyard. New they run about 100-140 bucks. Oh yeah, and welcome!

The sensor in the airbox is the Intake Air Sensor. Can you get a scan with them all plugged in while you drive? See if the IAT is reading at or above outside air temp, and how many grams per second you get at idle.

I've never had a MAF code before so I don't know if unplugging the IAT is supposed to help.

Well, I'm not sure it really helped, and now that I know what it is, I will reconnect it. All I can say for sure is that after I discoed it, the car didn't stall but the stalling is very intermittent, however once it started stalling it did so for like 15-30 minutes. It was to the point where initially I thought she had some bad gasoline or water in her fuel line.

I think it stalled because of the following: (please correct me if I'm wrong)

Once the ECM detects a MAF sensor (or any sensor) failure, it will go onto limp home mode, which runs the engine using predetermined set parameters for the air/fuel and ignition timing.

The spark plugs I removed from the car were absolutely grotesque, I think they might have been the original ones, 5/6 were completely black on the spark side and thread, and very rusty on the outside. The last one I removed, the one right above the sensor on the exhaust line, was cracked and came apart as I was taking it out, I'm glad I managed to get all of it out.

So under normal circumstances, the ECM could compensate for bad spark plugs by varying the ignition timing and air/fuel ratio, however in limp home mode...no.

Also the oil filter was a Mopar (Chrysler), I replaced it with a FRAM, and put Mobil 1 10W30 full synthetic in there. I used Champion Platinum spark plugs from Wal-Mart.

I was thinking of changing the PCV valve but I'm not sure where it is located on that engine, I will once I find it because there was too much oil in the car and that usually kills the PCV valve.

Thanks for letting me know which one it is, I will call auto parts stores tomorrow and shop for one.

Welcome to the family.

Fram fliters have a bad name around here. Purolator or a good WIX filter would be your best bet

Moving to 92-99

You need a MAF sensor from a 92-94 Buick LeSabre, Bonneville, or Olds with the 3800. Maf sensors in 95 and newer will not work for you.

Found one in a local scrapyard, 100$ with the old one in exchange.

I'm planning on replacing it tomorrow morning, I'll keep you posted on the results. I did start the car with the MAF in my hands, started right up and revved just fine.

Long enough to pull the power windows up as rain was rolling in. I shut it off afterwards.

Incidentally, other than disconnecting the battery for 30 seconds or so to reset the SES, is there anything else I should do after installing the MAF?

I've cleaned as much of the throttle body as possible with an old toothbrush and used compressed air to blow any particles out so they don't wind up in the carburation chamber.