Well, Lets start from the beginning. I have a 1994 929 that is just shy of 195K miles. I was working on replacing one of the belts one day and when I go to start the car it's backfiring like crazy. "no big deal" I think to myself, so I pull out of my driveway. That's when I knew something was wrong. There was practically 0 power to the back wheels and it was backfiring even more. Well, I literally hobble over the mechanics and he checks the timing (the first thing he thinks of) and finds out that that isn't the problem. Since he didn't have a scanner tool he could run any diagnostics on the engine but he could make a fairly good guess. he starts to thinking that it's one of the sensors so he pulls some of the connector pins out to see if it will change anything. Low and behold, when he pulls the MAF sensor out, nothing changes. Ok, that's not so bad I think to myself. I hobble on over to autozone and those pirates want ****ing $250 with a $60 core charge. This is outrageous.

So my question is. Does anyone know of anywhere that I could could get one cheaper? Or maybe if someone on this forum has a 929 that they are parting out I really need this car to be working again. I miss driving her.

 

Why would a bad MAF sensor cause backfire? Has the oxygen sensor ever been replaced? What belt did you change? Did you mess with any of the spark plug wires? Was the car backfiring when your mechanic checked the ignition timing? Did the mechanic disable the advance when he checked the timing? When was the timing belt changed last?

 

EDIT* didn't know that the car was rear wheel drive.

that aside, it could be anything from the MAF to the MAP to the o2 sensors. it could be the MAF fouling up the o2 sensor(s) or the other way around. i wouldn't put money on the MAP sensor though. the MAP will usually just make the car idle funny, but smooth. the o2 or MAF sensors are more than likely where it is.

do the salvage yard for an MAF to test your mechanic's theory. other than that, with the mileage on the car, i would do a compression test to see where it all sits. you could have blown a hole through a piston.

 

Do the 94"s even have a MAF sensor? I thought that systemcamemuch later, after OBDII was already the std.
I also thought that you either had one or the other, but not both? I would think MAP system on a 94.
For the record, I had a serious running problem w/my 3 and it turned out to be the MAF sensor.
It would start and idle just fine, but had no power. This got worsethe moreI stepped on the gas. The car would stall when I came to a stop... sometimes, but restart w/o a problem.

 

the 94 had a flapper style MAF. it was acually called an AFM, but it was basically the same thing. a lot of in-between (OBD and OBD II transitional) cars have both, but i think that the MAP is beginning to become more and more obsolete.