My German spec E34 issue list.... [Archive] - Bimmerfest - BMW Forums

: My German spec E34 issue list....

09-08-2008, 08:55 AM
Ok, I just picked up a 1991 German spec 525i with about 180k km on the ticker. Here are my issues:

1) It has developed a surging idle while stopped. I have been told that this is the idle air control valve that needs to be cleaned. Will be doing that this weekend. Will also be replacing air filter, fuel filter, plugs, oil change, and bleed and check brakes.

1a) While under the hood, I noticed that my MAF plug was not fully seated on the MAF sensor. So I plugged it in and seated it properly and my car instantly developed a very "lumpy" idle and then stalled. When I unplug my MAF sensor it goes right back to the surging idle. Does this mean that my MAF is bad? That would be my guess.

1b) When you unscrew and unplug the MAF sensor, the sensor end has like 7 pins or something, I didnt count. The plug that comes off has the corresponding holes. I know this may be a dumb question, but on the plug end, only some of the holes have metal contacts down in them. Is every hole supposed to have one of those metal contacts to make contact wth the sensor end?

2) The car is German spec, so all messages on the dash are obviously in German. It is showing two. First is "Bremsflussigkeit", which I found in the german manual as low brake fluid. Will address that this weekend when I do the brakes. Other is "Betriebsanleitg." I cant find that on anywhere in the manual. Anyone speak German or have a German spec car that you know what this means?

09-08-2008, 12:07 PM
The German display can be changed to English by putting the key into the ignition and turning it to position 1, now press and hold the right hand button on the instrument cluster for about 20 seconds. You can cycle through until you see English appear. Bingo now you have a English display. Hope this helps.

09-08-2008, 12:51 PM
Here's a list of items you can check to help resolve your idle problems.

attack eagle
09-08-2008, 10:01 PM
except that is an m30 and 3/4 of that list doens't apply to the m50...

I've had a lumpy/cam like idle for years... until I discovered that the brake booster check valve was supposed to have a nipple on it with a vacuum cap.
it had neither, just a hole. blocked that hole off, and got a sewing machine smooth idle.

bimmer dot info
09-09-2008, 07:35 AM
The MAF connector does not have contacts on pin 3 or 7. All of the others should.
Try resetting the computer and then reconnect the MAF. This should clear the stored codes and reset the fuel maps. If you get a CEL for the MAF after that it is bad. You should still clean the ICV.

09-09-2008, 12:24 PM
Oops should read the 525i info sorry.

09-11-2008, 05:53 AM
...and I reset the computer how?

bimmer dot info
09-11-2008, 07:48 AM
Disconnect the batter for a while (15 min or more). Dont forget to save any of the obc or trip info if you keep track of that stuff.

attack eagle
09-12-2008, 10:32 PM
and don;t forget you need the code if it still has the bmw radio.

Alternatively you can R&R the ECM to achieve the same thing without unplugging the battery

09-13-2008, 10:01 AM
...and once again, how do I "R&R the ECM"? :eeps:

attack eagle
09-13-2008, 11:29 AM
Open the e-box.

That is on the right side of the engine bay, same location opposite side from the fuse box.