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Got the exact same problem! (very long) (archive)

[ Follow Ups ] [ 5-series (E28) Message Board ] [ Msg. Board FAQ ]

Posted by GHBH on January 08, 2001 at 18:24:50:

In Reply to: AFM testing (SOS)!!!!!!!!! posted by Artem Grigortyev on January 08, 2001 at 15:47:12:

I think it is the AFM, at least in my car, it has the exact same symptoms as yours.

I have replaced, in the last year (not necessarily because of this problem): The ECU, all relays, all fuses, all vacuum lines, fuel pressure regulator, fuel filter, plugs, cap, rotor, valve adjust. Checked and cleaned the crank position sensor and the engine speed sensor (both checked out good electrically). Checked the resistance of the temp sensor, cold and hot, and it is fine. Maybe some other things I am forgetting.

I've also done the limited electrical checks you can do on the AFM (as described in the Bentley manual) and it checked out, I've also taken it apart and cleaned and lubed it. It seems to swing open smoothly.

I've also cleaned and lubed the aux air valve.

The frustrating part of my problem is that it is intermittent. The last time it happened, it started stumbling as I was accelerating from a stop light. As I gave it more throttle, it seemed like it wanted to catch on, but it sputtered to a stop. When I restarted it, it ran fine, but I could tell that during its episode, it was running very rich, because I could smell the fuel.

I've come to think its the AFM almost just by process of elimination! I have not pulled the trigger yet on the $300 purchase, as I'd like to be a *little* more sure.


My 535i 86 is about to die again. Before, when you would accelerate, the engine cut out for a second (which was accompanied with a nice jerk!) but then it would keep going again. For some reason, I also didn't have any power. Now it is acting even worse. Even in neutral (5sp manual), when you push the accelerator, you have to wait until it would actually rev up. Needless to say that it is not accelerating at all (Takes forever starting on 1st). What is interesting if you get beyond 3000 rpm it actually starts accelerating. May be it is my AFM? I got it here and the flapper door seems to move smoothly. Can I check for resistance?

Lately I replaced airfilter, spark plugs, fuel filter and fuel pressure regulator.

I have to get home somehow (right now I'm at work) and besides I'm working on my wife’s 528e (VALVE JOB!) so I don't really have time for this crap.

Any suggestions would be appreciated





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