e30 idle

[BlowMyWhistle 0]

Hi Y'all, I'm so over this car! '90 320i auto.

We've had problems with this thing since we bought it.

We took it into the German (peters master mechanic) and he reset the computer, a few minor faults was all, and he pushed up the idle to compensate for it cutting out.

Now my baby comes round, stressed, her car's still not right, so somehow She goes off in my car again!

So i cant see anything wrong with it, the idle is about 1500 rpm, but if you kick it, it drops to 7-800.

So went back to the German, but He's off today, so went into see Andy at Beemer Motor Works, he spent 5 minutes on it and pulled the idle down, twiddled with the afm a bit and had it running nicely (ear-ometer).

But sitting at the lights it starts playing up again, un der load, the idle will dip and then catch again.

I was reading up about this and think it might be a correlation between the throttle body not closing properly and the circuit for running the icv? Or the throttle position sensor? Runs like a vacuum leak, witch it isn't!

I'm not sure, but I'm sick of trying to fix it!

I'll go back and see the German and run this by Him as soon as He surfaces again. He's full on busy with Mercs and Porsches etc. Have to book in a week or 2 in advance.

Is there anytihng along these lines that comes 'under the radar' on a diagnosis?

Pretty sure I was reading a post here last night about this, but can't find it?

Cheers y'all

I'm so over this thing! i'ma gunner buy a new computer and afm I think, they both out of other cars!It idles so rough, doesn't miss so much, but like the timing is out a fraction, like a pre-ignition?

Idle Control Module????

Think I'll take a video, post that, sick of trying to describe what it's doing!

Runs fine for a while, then gives a lurch and starts farting around??

Edit: cant see no ICM, is it under the dash behind the dme or something?

I've been told to give it a tap, but apparently some models don't have one??

Looking for a green box?

I've eliminated the Throttle Control switch, it wont run without it, and I had it looked at, it's okay!

Still thinking the butterfly valve is not closing properly? reading like a vacuum leak with all associated symptoms.

It's been suggested an injector boot pinched? Expands when the cars warm allowing a vacuum leak?

But my favourite theory is the afm butterfly valve.

Wow 43 reads, but no replies!

I go back to work next week, so We'll take it back, and leave it there until it's fixed, or drive it over a cliff.

To Andy at Beemer Motor Works, The German is stumped, and has a Maserati to fix first..

Any suggestions?

Edited August 19, 2011 by BlowMyWhistle