Wierd Problem -very frustrated - United Bimmer Community

**mavricbmw** · 12-29-2009, 12:14 AM

Hi guys, my brother in law has a Bmw e36 1996 316i, if i hold the car revs at 2000rpm, it drops to 1500rpm, and it continues to jump between the 2, so far i've cleaned the throttle body, both sensors (TPS) throttle position sensor and the (ICV) Idle control valve, ive also replaced the Positive Crankshat Valve. the (MAF) Mass airflow meter has been reset by agents to what they believe is right and so far i get the same issue, i've noticed that when i disconnect (TPS) it stops the issue, however i went to the spares place and tested one of theirs on the car and it does the same thing. guys any idea's and advice will be most apreciated.

**3050rpm** · 12-29-2009, 11:20 AM

It seems to me you've gone through just about everything there is, except for vacuum leaks coming from a cracked hose, so inspect the hoses and replace where necessary.

**mavricbmw** · 12-29-2009, 12:07 PM

3050rpm thanks for the reply, i thought that might be the outcome, i'm just not so sure about the MAF now, as i've tried to get as much info from my brother in law as posible and i've found out when the "set" the MAF, they told him they couldnt do it via the screw on the side, they cut the thing open and moved the dial inside, i dont know, they charged him for a diagnostic, then charged him to set the Maf and still it not right, i also remember that at one stage the car was in a storm, the rain flooded the computer box and the car wouldnt start, the computer was repaired, is that a possible problem aswell. he cant remember if it gave the problems before or after the storm. thanks for the help so far. chris

**3050rpm** · 12-30-2009, 11:52 AM

Ooo, not a good sign that the MAF essentially got the sledgehammer treatment, that's a rather delicate component performing the important function of establishing the proper air:fuel ratio. If it couldn't do that, then apart from its own failure (possible, but I rather doubt it), it means the problem rests elsewhere. I wouldn't trust a place that is so ignorant of modern intake systems as not to bother getting an intelligent diagnosis and start fooling with the MAF.

As to the computer, again I'd say it's possible, but doubtful, as you said it was repaired or replaced, and your brother isn't clear on whether the current problem occurred before or after the drenching. Something like that would probably be remembered on the time scale.

If it's possible to do, and you're capable of the work, reset the MAF and start looking elsewhere for culprits. Worst case, you might need a new one and a session in smalls claims court to get your money back from those hamfisted clowns.

**mavricbmw** · 12-31-2009, 09:36 AM

thanks so much for the help and direction in this issue, i really apreciate you taking the time to help, in the new year, we will source an air flow meter, as in the back of my mind the teribble repair job on the MAF has bothered me. like i've tried to explain to my brother, we were never 100% sure that the MAF was right. so rekon a good place to start is that, it wont hurt the car if it doesnt solve the problem it actually helps with future problems as my and his bmw are both over 340000 km's, mine obvouisly will out last as i've been serviceing and looking after it for the past 3 years, while his has been in and out of different workshops.

thanks again and have a great new year