Mass Air Flow Sensor

I have had an ongoing problem with my 1996 sunfire gt running rough and stalling out in very hot weather.. I would need to let the car sit for at least an hour or so to "cool" off b4 I could restart it.. If i did manage to keep it gong without stalling especially from a stop, it would flutter and hesitate like mad..I have had diagnostics done.. no one was able to retrieve any codes.. untill just recently.. and that was with some pushing many buttons and different programs ( so I am told).. either way i have been told that it is the MASS AIR FLOW SENSOR.. Could someone please tell me where that is located and is this an expensive part to fix?

Thanks in advance:banghead:

Look at the air filter the appx 4 inch diameter hose that comes from the air filter. The Maf will have a electrical plug on it and be in this hose.

Lots of folks 'tellin' stuff, huh? Words go away when the sound stops. Get it in writing, otherwise, let the sounds go out the other ear.

Do a few free diagnostic tests; fuel pressure (see you tube vid 'fuel pressure test'), and check for vacuum leaks:
Loping idle is vacuum leak. 30 year old lawnmower, or a new car on the lot. If it sucks air where it ain't supposed to, it lopes.

Brick on pedal, block TB arm, anything to get a STEADY idle. 1200rpms or so... Feed starting fluid spray, A LITTLE AT A TIME, EVERYWHERE. Rev increase is the leak.

In a tough spot to pinpoint? Light a book of matches, blow it out while the heads are burnin', and feed the smoke to the leak.

Both of these problems are common, and will trip no codes...

Lots of folks 'tellin' stuff, huh? Words go away when the sound stops. Get it in writing, otherwise, let the sounds go out the other ear.

Do a few free diagnostic tests; fuel pressure (see you tube vid 'fuel pressure test'), and check for vacuum leaks:


Both of these problems are common, and will trip no codes...
Thank you for your reply.. I appreciate it.. lol.. I did see the OBD II and saw that the MAF was the problem.. He tried to clear the code.. but it wouldnt clear.. either way.. i believe it has to be replaced..I was just unsure of where it was located.. (I never asked at that moment as it was a busy night).. and if it was a very costly venture... thanks again for any input.

One more thing i did realize later is that the "breather" where the air filter sits is broken.. as in wont stay on.. not sure what happened there.. either way, will this affect how the sensor works? Then again, i suppose that could be classified as a "vacuum leak"?

Look at the air filter the appx 4 inch diameter hose that comes from the air filter. The Maf will have a electrical plug on it and be in this hose.
Thanks for ur reply.. I will take a peek and locate it..

I would make a trip to a scrap yard and buy replacements for the broken pieces. A lot of MAF's are sold on ebay just buy a new or rebuilt unit.

One more thing i did realize later is that the "breather" where the air filter sits is broken.. as in wont stay on.. not sure what happened there.. either way, will this affect how the sensor works? Then again, i suppose that could be classified as a "vacuum leak"?

Any air entering the system past the MAF sensor will cause an erroueous reading and the computer "sees" less air than what is actually going into the engine. It wouldn't actually be a vacuum leak, as there is no vacuum outside the throttle body, but would cause unmetered air to enter the engine. Unless someone is sure that there is a MAF sensor on this engine, I really don't think there is on any of the GM 4 cylinders (and I'm 99% on the quad-4). That said, don't spend a lot of time looking for it. A bad MAP sensor can cause a MAF code.

Any air entering the system past the MAF sensor will cause an erroueous reading and the computer "sees" less air than what is actually going into the engine. It wouldn't actually be a vacuum leak, as there is no vacuum outside the throttle body, but would cause unmetered air to enter the engine. Unless someone is sure that there is a MAF sensor on this engine, I really don't think there is on any of the GM 4 cylinders (and I'm 99% on the quad-4). That said, don't spend a lot of time looking for it. A bad MAP sensor can cause a MAF code.
Thanks for the reply.. that would definately explain then why no one would carry such a part.. (and no one seemed to know that there wasnt one) lol..and I was told to ask the dealer for the part.. :s.. Also the Haynes manual doesnt even mention anything about a MAF sensor, only the MAP sensor.. so again.. you seem to have given the best answer yet!.. thanks to all who have replied tho.. :-))

on this engine the maf sensor doesn't exist, as stated in an earlier post. If it is a map sensor prob it may just be the vac line leading to the sensor, not the sensor itself. the vac line was rotten on my 97 w/2.4 engine and I've heard of many others with similar prolems.

I have had an ongoing problem with my 1996 sunfire gt running rough and stalling out in very hot weather.. I would need to let the car sit for at least an hour or so to "cool" off b4 I could restart it.. If i did manage to keep it gong without stalling especially from a stop, it would flutter and hesitate like mad..I have had diagnostics done.. no one was able to retrieve any codes.. untill just recently.. and that was with some pushing many buttons and different programs ( so I am told).. either way i have been told that it is the MASS AIR FLOW SENSOR.. Could someone please tell me where that is located and is this an expensive part to fix?

Thanks in advance:banghead:

If you don't know cars well, that's no big deal.

But if a mechanic says something is wrong, DON'T OK ANY WORK, UNTIL HE SHOWS YOU WHAT THE PROBLEM IS.

For example, he says the fuel PUMP is bad. Get him to SHOW you a fuel pressure gauge connected to the pressure gauge fitting, that shows LOW/NO pump pressure. THEN, get him to SHOW you, IN WRITING, what the pressure is supposed to be.

Or, the MAF is bad. Get him to show you on the computer, that the sensor is not showing proper readings, and that it has or has not 12V current like it is supposed to.

If you don't protect your wallet, no one else will either.

Tell the doctor you have a headache.

"Amputate."

Cures headaches every time. :lol:

ok.. again thanks for ur reply.. i assumed that it would be the MAP sensor or a vacuum line as there is no MAF sensor on these engines as stated earlier.. :)

If you don't know cars well, that's no big deal.

But if a mechanic says something is wrong, DON'T OK ANY WORK, UNTIL HE SHOWS YOU WHAT THE PROBLEM IS.

For example, he says the fuel PUMP is bad. Get him to SHOW you a fuel pressure gauge connected to the pressure gauge fitting, that shows LOW/NO pump pressure. THEN, get him to SHOW you, IN WRITING, what the pressure is supposed to be.

Or, the MAF is bad. Get him to show you on the computer, that the sensor is not showing proper readings, and that it has or has not 12V current like it is supposed to.

If you don't protect your wallet, no one else will either.

Tell the doctor you have a headache.

"Amputate."

Cures headaches every time. :lol:
thanks for your reply.. and yes absolutely will i make sure that I see the problem b4 any work is ok'd by a mechanic
:D