Idle problems & Instrument Cluster

[montokboy]

I have had an ongoing issue with my 1986 e30. The idle is irregular, and a bmw mechanic tried for 4 days to diagnose without real results. The needle just doesn't want to stay put (this is not an SI problem either, since the engine shudders in relation to the needle) I had the idle control valve changed and still nothing. Would anyone out there happen to have the same problem and successfully diagnosed it? My mechanic is now telling me that it's an electrical issue. I had the engine changed a few months back and the problem started after that. I also wonder if having the Turner chip would change anything, thinking the specs were set to the car's original chip.

Secondly I have read and have had problems with my instrument cluster, being this is a common problem. I changed the whole cluster and got the SI board to work but the solder joints seem to not hold up, since the temp guage was on n off and now dead. I used to hit the side of the dash and it would come alive, but no more. I think I need to replace the whole SI board which is about $150.00. I have had no luck with finding a properly working cluster off ebay or otherwise.

Also, has anyone had experience changing out the lock actuator on this car? if so s it easy?



thanks
Sean

 

[BMWbry]

Mine idled like crap until one day it went kaput. I peeled off the air flow meter cover and moved the black gear counter-clock wise 4 clicks. Helped out a lot. Your check engine light will be on, but after it adjust it goes away. Just mark where the original hole was and mess around with it.

 

[ldzpstnr]

Id could be the idle control computer. What does it do exactly? Does it just change in RPM by a little bit, like a few hundred or does it reve up and down in large increments like... 500 rpm or 1000.

I had a 318i that would rev up and down a lot. I replaced the idle control valve and it didnt change much. I then replaced the idle control module and it was fixed. The module is up around the ECU module in the glove box. Its a small unit, mine was made by VDO.

Now my '87 325 had a more "suttle" idle problem. It would only change in a little bits, like a couple hundred RPMs. A mechanic friend of mine said to check all the electrical sensor connectors throughout the car, as one of them might be a little corroded from moisture. So I did that and it went away.

His reasoning was that if a sensor was not makng good enough contact that it would make the ECU go in and of open loop and closed loop mfode, causing it to change the ingition timing and thus the RPMS. Made sense to me so I did it and now no more idle problems.

Just my opinion here, but stuff worth checking I think. Later

Aaron

 

[montokboy]

idle irregular

Thanks for the info, I had the idle control valve also changed and it did nothing, I'll look into replacing the module. The electrical systems in these cars is disappointing, I have had several problems with shorts. Even my audio system has moments. I'm guessing if the electrical is to blame to first check in areas water/moisture could have got in.

thanks
Sean