Crank, crank.....

[rep]

1989 525I: when starting 75% of the time, the engine cranks way too long before starting. Once it starts, it runs over rich for about 30 seconds then idles properly. Three BMW dealers have been unable to solve the problem. They have basically given up. Any thoughts. The idle control valve and injector temperature sensor have been replaced.

[Javier]

fuel system between check valve at the pump and the pressure regulator at the injector rail. Have you checked pressure behavior at different points of the starting up operation?

[632 Regal]

Check your fuel pressure, might be a weak pump causing the extended cranking time.

[Jon K]

Check your fuel pressure, might be a weak pump causing the extended cranking time.

.... '89 525.... not a nikasil

[ocampg]

I am having the same problem on my 89 525i. Only, now, my engine is stumbling/misfiring. Almost seems like a fuel related problem. I haven't checked pressure since that is beyond my mechanical scope. I have replaced O2 sensor, plugs, wires, cap, rotor, and throttle position sensor. Though they seemed to only fix it temporarily. Now the engine is stumbling ALL the time. It seems to run ok, if I have the throttle open past about 4000 RPM on the highway, otherwise, it stumbles along and stalls out. I finally dropped it off at an indy this morning. I will let you know what comes of it, also, if you have any suggestions or if you have fixed it already, let me know what the solution was. Thanks,
Geoff

[Jon K]

I am having the same problem on my 89 525i. Only, now, my engine is stumbling/misfiring. Almost seems like a fuel related problem. I haven't checked pressure since that is beyond my mechanical scope. I have replaced O2 sensor, plugs, wires, cap, rotor, and throttle position sensor. Though they seemed to only fix it temporarily. Now the engine is stumbling ALL the time. It seems to run ok, if I have the throttle open past about 4000 RPM on the highway, otherwise, it stumbles along and stalls out. I finally dropped it off at an indy this morning. I will let you know what comes of it, also, if you have any suggestions or if you have fixed it already, let me know what the solution was. Thanks,
Geoff

If it were an M50 i'd recommend coils. Have you replaced fuel filter? Also check your fuel lines for a leak? Those two things are relatively easy. We will see what comes of it.

[ocampg]

Indy got back to me. says I need to replace the MAF Sensor. This is a $300 part! Damn!! To answer your question though, I have replaced the fuel filter and I dont think there are any leaks since there is no smell of fuel anywhere around the car. Does anybody know a further way to test the MAF sensor? I would like to verify that it is indeed broken. Does this show up on a stomp test? Are there two pins which I can measure a changing resistance or voltage relative to the "barn door" position? Lastly, is anybody parting out an 89 525i that wants to sell me their MAF sensor cheap? Thank you in advance
geoff

[shortbuss2336]

Indy got back to me. says I need to replace the MAF Sensor. This is a $300 part! Damn!! To answer your question though, I have replaced the fuel filter and I dont think there are any leaks since there is no smell of fuel anywhere around the car. Does anybody know a further way to test the MAF sensor? I would like to verify that it is indeed broken. Does this show up on a stomp test? Are there two pins which I can measure a changing resistance or voltage relative to the "barn door" position? Lastly, is anybody parting out an 89 525i that wants to sell me their MAF sensor cheap? Thank you in advance
geoff

[rep]

After all of my failed attempts to get my car fixed, no one ever mentioned this sensor. Exactly, what does it control? I do not want to keep replacing good parts.