91 Regal 3.8L Possible MAF Sensor Problem

Hi there

I have the same problem in my 91 regal 3.8L. I just tried what you suggested - unplugged the MAF and bingo - it seems to run great. However, i went to the automotive store and bought a new one for 250 bucks and installed it. However, I still have the same problem.

Is there anything else i can try? Do you think it could be the fuel pump? The car seems to run fine when i unplug the MAF sensor. and, oh, i just replaced my fuel filter after about 5 years.

I appreciate any help you guys can provide - this problem has been plaguing me for 3 months!!

Thanks to all.

Hi there

I have the same problem in my 91 regal 3.8L. I just tried what you suggested - unplugged the MAF and bingo - it seems to run great. However, i went to the automotive store and bought a new one for 250 bucks and installed it. However, I still have the same problem.

Is there anything else i can try? Do you think it could be the fuel pump? The car seems to run fine when i unplug the MAF sensor. and, oh, i just replaced my fuel filter after about 5 years.

I appreciate any help you guys can provide - this problem has been plaguing me for 3 months!!

Thanks to all.

I'm not sure but the same test may not work on a Series I 3800 versus Series II 3800. The PCM module may not be resetting. There are differences between odb-i and odb-ii and the way the PCM works.

I would assume that unplugging the MAF may have fixed your problem. What brand MAF sensor did you get and at what supplier? I've run into bad MAF sensors off the shelf from parts stores like AZ. Especially if they were A1 Cardone remanufactured.

With MAF disconnected the car should operate normally including hard WOT acceleration which would rule out a fuel problem. If the fuel pump were bad you would not have driveability even with the MAF sensor disconnected.

You can test fuel pressure at the front fuel injector rail. There should be a Schrader valve to hook up to.

Hope the info helps. Good luck!

Thanks very much for replying.. i am at wits end with this thing. The MAF sensor I bought from Canadian Tire is a Nieoff brand. I bought a used one from the junk yard too - 30 bucks. the Nieoff is brand new, cost me 250 including taxes. Should i just bite the bullet and buy from the dealership? they charge over 300 bucks.

Are there known issues with Nieoffs being defective right out of the box?

Thanks very much for replying.. i am at wits end with this thing. The MAF sensor I bought from Canadian Tire is a Nieoff brand. I bought a used one from the junk yard too - 30 bucks. the Nieoff is brand new, cost me 250 including taxes. Should i just bite the bullet and buy from the dealership? they charge over 300 bucks.

Are there known issues with Nieoffs being defective right out of the box?

I am not familiar with the Nieof aftermarket brand. From what I can see you have tried one new MAF and a used. So I really don't know if it is worth trying a GM MAF sensor (third) at the higher cost. Have you checked fuel pressure?

BTW - I started a new thread/post for you separate from the 2000 model Regal having MAF sensor problems. Too confusing to keep them together.

Hello,

Your problem probably isn't with the MAF, if you tried two other ones. I certainly would'nt waste the money on GM parts. Especially since you tried twice already with other parts, chances are against bad parts. I have an 88 and have had MAF problems, but solved them. So what does your car do, because it doesn't say in your post? I'll try to help you any way I can. My manual and code definitions should lead us in the proper direction, if I have an idea of what your car is doing, then maybe we can pinpoint the sucker!

MJ

Hi Everyone, thanks for trying to help me out.

I just went back to the junkyard today and swapped for another MAF sensor. It seems to run a touch better before it up and quits. I had it running a few times before it stopped.

The problem is when the MAF sensor is unplugged, it runs fine. When it is plugged in, it wont start. The engine turns over, but when i release the key the engine will die almost immediately.

Fuel filter was just changed and fuel pump seems to work okay.

The MAF sensor from the junkyard I got today said it was from a 95 regal - so 4 years newer - don't know if that helps or not...

At this point i'm thinking of just biting the bullet and ordering a GM MAF sensor online unless someone has something else i can check?

Thanks again!

Hi, I did read that when a MAF is unplugged and it runs better, usually it's a bad MAF. BUT I have seen a case where the MAF wasn't bad and doing the same as yours. In that case, it was narrowed down to two things. 1) MAF relay or 2) bad wires in plug to ECM. Relays should be under the hood and I'm not sure about the ECM location on yours, mine is under the passenger side dash, I think. Hope this helps!