1998 V70 GLT stalling\stumbling problems. MAF issues.

AudiDefector · Post by **AudiDefector** » 12 Nov 2009, 11:00

Hello. I have a 1998 V70 GLT that suddenly started stalling at stop lights. Would sometimes restart, other times it wouldn't. If it did restart, it would run very rich. Had it towed home, and did some testing. Fuel filter is new. Fuel pressure is running anywhere from 38 pounds at idle to 45 pounds at rev. Seems good to me.

So, based on a suggestion on a forum, I unplugged the connector to the Mass Airflow Sensor. Guess what? She started and idled. Even ran down the road pretty nice with just a minor degradation in performance, which I would expect running in a "backup" mode.

Went out and bought a new MAF sensor and replaced it. No dice. Car does not like to start without giving a bit of throttle(like an old carb car). When it does start, it idles rough and stalls. Go back and unplug the MAF sensor, and it runs fine. I have checked high and low for vacuum leaks. Anyone have and experience with this, or ideas for me to try?

Thanks in advance.

Post by **misha** » 12 Nov 2009, 11:05

Did you bought original Bosch(0 280 217 107) Maf sensor or something unbranded?

AudiDefector · Post by **AudiDefector** » 15 Nov 2009, 11:51

Misha,

Your question to me, happened to also be the answer.

I bought an AutoZone MAF rebuilt by A1 Cardone. It didn't work, right out of the box.

My mechanic "borrowed" a used MAF off of a salvage yard V70, and she came right to life and purred like a kitten. So, I went out and got a Bosch MAF, and it works beautiful.

Problem resolved.

Post by **misha** » 15 Nov 2009, 16:20

Well done!

Post by **nuyrks70** » 15 Nov 2009, 20:31

just curious, did you trash the MAFS yet?
Mine ran rough when cold and threw a P1118 code which converted to MAF sensor upper limit.

I removed it and with a strong light I was able to see a tan/brown coating, covering the components. I bought CRC MAF cleaner for $5.00, Sprayed it a few times and the dirt was gone. I let it dry, reinstalled it and the problem was solved.

Check yours just to see if it is extremly dirty, that may have been your problem. I was told that these need to be cleaned to ensure optimum air fuel efficiency especially in a high mileage car and certainly if it throws a code it may not be a component failure. I guess they were right, in my case, a dirty residue was the culpret.

Someone explained that tiny fibers from the air filter combined with moisture, clings to the components as they pass through the sensor. The residue was the same color as the filter paper.........makes sense to me

AudiDefector · Post by **AudiDefector** » 16 Nov 2009, 10:39

Unfortunately, Autozone took my original MAF as a core for their defective turd of a part. When I returned the MAF to them, they had already discarded my old MAF.