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5-Series (E12,E28, E34, E39, E60) Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)

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Old 08-27-2005, 09:37 AM   #1 (permalink)
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Greetings everyone,
I have spent a great deal of time searching this and other boards in hopes of finding resolution to my 92 535i bmw's problem. Let run down the list and see what you guys think. This is my first Bmw and I've sold all my other cars since then, Now I know why people love BMW's!

Here ya go:
Checked ecu and it is throwing a 1215 code which means it's the MAF sensor, from what I've read after read and using the pedal method to extract the code.

So last night I disassmbled the MAF sensor and cleaned it with some Circuit cleaner. I also checked the connections. put it back together after spraying the intake with carb cleaner.

I'm still having trouble starting the car when the motor is cold. After is finally starts I have to hold the gas to kepp it from dying out. After a few minutes it warms up I drive approx. 1-2 miles down the road and when I slow down to a light or stop for coffee it will either die and the eml light trigger or when I try to restart it after getting coffee will have trouble starting. This is can be dupluicated every morning like clock work. Once the car has warmed and goes through this cycle it will start with no trouble as long as the motor is still warm.

Here is another synptom, If I go to run errands with the wife and she is running in and out of stores and I sit in the car and wait (idle ) sometimes when backing up after sitting there a while the car will die and the dreaded eml light kick on!

Has anyone else had the same problem or can anyone tell me this is common for a MAF sensor. I'm thinking when warm the system runs off a open loop and cold it runs off a closed loop.

HELP
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Old 08-27-2005, 10:32 AM   #2 (permalink)
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http://shrubbery.student.utwente.nl/ should give you all you need to know reference the MAF. In my case (1988, 750il) I bought two used ones and motored on.
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Old 08-27-2005, 11:42 AM   #3 (permalink)
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Originally posted by Bear@Aug 27 2005, 10:32 AM
http://shrubbery.student.utwente.nl/ should give you all you need to know reference the MAF. In my case (1988, 750il) I bought two used ones and motored on.
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Thanks fpr the response that helps alot actually... Can anyone tell me what the voltage should read out on a MAF for my 92 525 e34 automatic ? I think it's only 4 wires and the plug is rectangular not circualr like the 7 series...
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Old 08-27-2005, 11:43 AM   #4 (permalink)
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I meant 535 not 525 sorry noob
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Old 08-27-2005, 02:56 PM   #5 (permalink)
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In reality what you have is a AFM (Air Flow Meter) vers a MAF. Take a look at www.bmwe34.net and look at the engine fixes, the AFM adjustment is dixcussed.
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Old 08-27-2005, 11:58 PM   #6 (permalink)
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Also keep in mind that on these earlier cars the fault code 41 (AFM) was often times caused by a faulty idle valve. Personally thats the 1st thing that I'd check.

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Old 08-28-2005, 08:30 AM   #7 (permalink)
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Originally posted by Dirty_Tool@Aug 27 2005, 11:58 PM
Also keep in mind that on these earlier cars the fault code 41 (AFM) was often times caused by a faulty idle valve. Personally thats the 1st thing that I'd check.

DT
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Ok, so I went out to start her up this morning and instead of sitting there and trying to start it like I do every morning. This morning after I wasn't able to start her after 3 tries I disconnected the AFM at the harness and it started after only 2 tries. It idleled really rough and then I plugged the harness back in and it began to idle better.

If it's a faulty idle valve, is starting issuses a common problem.

Thanks again for everyones help!
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Old 08-28-2005, 10:17 AM   #8 (permalink)
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ohh, about air flow meter --- i had a problem with it on my car and what would happen is it would start up and shut off right away, and the only way to keep it running was holding the gas pedal... --- this is exactly what your problem is, if i'm not mistaken...
FYI -AFM cannot break
what you do is clean it and it works again
happened with my car, and that what was recommended by a guy who was working at the dealership.. however, i'm not exactly sure what you clean it with cuz my brother did it, but all you need to do is clean it - no need to replace it because like i said, i am pretty sure the guy at the dealership said it can't break!

by AFM i mean Air Flow sensor
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Old 08-28-2005, 02:25 PM   #9 (permalink)
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Originally posted by superdeadman@Aug 28 2005, 10:17 AM
ohh, about air flow meter --- i had a problem with it on my car and what would happen is it would start up and shut off right away, and the only way to keep it running was holding the gas pedal... --- this is exactly what your problem is, if i'm not mistaken...
FYI -AFM cannot break
what you do is clean it and it works again
happened with my car, and that what was recommended by a guy who was working at the dealership.. however, i'm not exactly sure what you clean it with cuz my brother did it, but all you need to do is clean it - no need to replace it because like i said, i am pretty sure the guy at the dealership said it can't break!

by AFM i mean Air Flow sensor
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This is exactly how mine behaves! Could you point me in the right direction to find out what I should use to clean mine with?
I went outside amd disconnected the battery and then rehooked it up after about 15 minutes. The car fired right up after doing this with no problems. Is it possible that since I never reset the ecu after cleaning everything it was still running the same way because the computer didn't know any better?
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Old 08-31-2005, 08:44 PM   #10 (permalink)
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Ok so here's an update...

I cleaned the AFM and reset the ecu and this doesn't seem to have fixed it. I thought it did initially but after trying to start it this morning it is still having issues.

AFM' s are expensive and before I spend the money I want to make sure this is the issue. Can anyone give me the ohms or voltmeter readings that I should read on the wires coming off the meter.

Oh and one more peice to the puzzle if I let the car idle the EML light will come on after it sits there for a little while idling. The car will continue idling the same even if the lite comes on but if I tap the gas the engine will die...??
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Old 09-08-2005, 11:57 AM   #11 (permalink)
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Ok here`s an update I replaced the afm with a new one and changed out the filter. The car seems to be back to normal!

I am no longer experiencing...
- the car starts and then imediatly dies and then has trouble starting or will just crank car had spark and fuel both confirmed.
- pedal has to be held in upon start to keep car running.
- rough/low idle
- sporatically dies while driving for no reason, that or goes into limp mode (EML) and dies
- Gas milage goes to crap
- Check engine light would come on when car wouldn`t start or would die with code 1215. The light would eventually go out.
- Car ran perfect after the car had warmed up and driven around a while
- trying to start the car became progressivly tougher and would require me holding the pedal in to fire up. When it did fire up it had trouble building RPMs, behavior similar to a turbo car spooling.

I bought the car used and it has a cold air intake on it. The filter was black and probaly oiled at some point. I have no doubt this led to the AFm`s eventual death.

I will keep everyone posted if this doesn`t work out with the new part but I think I got this figured out I hope this helps alot of people that have spent hours online looking up these type of symptoms.
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Old 10-23-2005, 01:16 PM   #12 (permalink)
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It's Back!!!

HELP So I think the AFM that was replaced 2 months ago is shot... This time I was able to do a bench test on the resistance OHM' s and compared the old unit with the new unit.

What is the correct starting resistance for the flap and temperature sensor.

I tested the old one and the temp sensor's ohms wil climb and continue climbing till I take the tester tips off.

The new one air temp sensor stays the same unless you blow air on it.

My car will ussually run fine but is doing the same thing that it use to. I replaced the AFM and the car ran great for a couple months but is now beginning to act up...
BTW I changed the plugs cleaned the throttle body, and injectors. When the car won't start it is getting fuel, spark but no air. Infact I was able to give it air to start but had to open the flap to the AFM a little bit.
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Old 10-24-2005, 12:31 AM   #13 (permalink)
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Could it be a vacuum leak? Do you hear any whistling or whooshing sound from the engine?
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