MAF problem solved
Thread Starter
TECH Apprentice
Joined: Jul 2002
Posts: 393
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From: Tucson, AZ
MAF problem solved I thought I'd share my experience with MAF in my '99 M6 z28
The problem appeared gradually about an year ago. At that time I had a ported, but not descreened MAF on the car for about an year, the car run flawlessly and posted some of the best times/MPH for it's mods here in Tucson (13.3 & 107mph at 3075' elevation on a lid&catback M6 z28).
I noticed some knocking at high rpm, but it was summer time, and I thought it's just heat. But it didn't go away when heat ended. In fact, it got worse, I couldn't get above 4krpm without that marble sound. I checked out the fuel system and changed the fuel filter, and it got a little bit better, but not for long. So I got an EFILive and as it turned out, the car had 25+ LTFT's, not only at WOT, but anytime I pressed on the gas. So I got MAFT and tuned to the point that it was -10 LTFT's at idle. However as soon as I gave it just a little gas (still closed loop), LTFT's would go positive. More gas - and they would go to 25. At this point I started to look very closely at MAF signal. It looked low to me, so I took it off the car, disassembled and looked at the wires (I still have the screen).
The resistors were CLOGGED with some blackish residue
Apparently air filter didn't do a very good job, and since the car has almost 80k miles on it, the MAF wires just got extremely dirty. So I used lots of alcohol and paper tissue to VERY carefully clean the wires. And it worked like a charm. I put the MAF back on the car, and it went to WOT the way it used to 2 years ago. Chirped tires on 2-3 shift.
So - for those of you having problems with your MAF - it might be worth it to take a closer look at the MAF itself. As time and miles go by, the wires may simply become dirty and your precious MAF calibration simply goes
The problem appeared gradually about an year ago. At that time I had a ported, but not descreened MAF on the car for about an year, the car run flawlessly and posted some of the best times/MPH for it's mods here in Tucson (13.3 & 107mph at 3075' elevation on a lid&catback M6 z28).
I noticed some knocking at high rpm, but it was summer time, and I thought it's just heat. But it didn't go away when heat ended. In fact, it got worse, I couldn't get above 4krpm without that marble sound. I checked out the fuel system and changed the fuel filter, and it got a little bit better, but not for long. So I got an EFILive and as it turned out, the car had 25+ LTFT's, not only at WOT, but anytime I pressed on the gas. So I got MAFT and tuned to the point that it was -10 LTFT's at idle. However as soon as I gave it just a little gas (still closed loop), LTFT's would go positive. More gas - and they would go to 25. At this point I started to look very closely at MAF signal. It looked low to me, so I took it off the car, disassembled and looked at the wires (I still have the screen).
The resistors were CLOGGED with some blackish residue
Apparently air filter didn't do a very good job, and since the car has almost 80k miles on it, the MAF wires just got extremely dirty. So I used lots of alcohol and paper tissue to VERY carefully clean the wires. And it worked like a charm. I put the MAF back on the car, and it went to WOT the way it used to 2 years ago. Chirped tires on 2-3 shift.
So - for those of you having problems with your MAF - it might be worth it to take a closer look at the MAF itself. As time and miles go by, the wires may simply become dirty and your precious MAF calibration simply goes
Thread Starter
TECH Apprentice
Joined: Jul 2002
Posts: 393
Likes: 0
From: Tucson, AZ
Originally Posted by jimmyblue
Was this with a paper filter, or one of the
oiled foam ones?
oiled foam ones?
