E30 M3 strange idle

[John Goddard <jgoddard@xxxxxxxxxxxx>]

I had a a problem like that.  Check out the Idle Control Valve.  It's under
the air intake plenum.  I think I had to remove the plenum from the intake
manifold to get to it. The valve is about the size of a flashlight and has
air hoses in/out, to control warm air when engine is cold.  The valve gets
really junked up with carbon, and the valve gets stuck.  I suppose you
could probably clean it, but I just got a new one.

There is also a microswitch on the front end of the throttle shaft which
senses closed throttle. Could be out of adjustment.  See ETM for correct
output.

John Goddard
88 M3
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Date: Mon, 5 Oct 1998 13:58:18 -0500 (EST) 
From: Seung Hyun Chung <schung@domain.elided> 
Subject: Strange E30 M3 problem
I have an E30 M3 with a strange problem. The RPM refuses to drop down to 
800 or so when it idles.When the car is at idle, the RPM is around 3000, 
2000, 1500, or where ever the car wants it to be. I waited a day to see 
if the problem would disappear but it didn't. Once in awhile the RPM comes 
back to its normal level. This problem comes and goes. I could also feel 
it happening when I'm driving. Sometimes when I lift off the gas, the car 
keeps going as if the cruise control is activated. When I push on the 
clutch, the RPM hovers around 3000.
I have already checked to see if the throttle body linkage or the 
accelerator cable is sticking. They are both fine.
Could it be the Air flow meter sticking? One thing I do notice when this 
phenomenon happens is that the car seems to be running rich, very rich. 
At times, I could smell the sulfur from my exhaust.
Any ideas? Experiences?
I need to correct this problem as soon as possible. Everyone waiting 
for the green light thinks I want to race them. 
Please e-mail directly: 
schung@domain.elided 
seunghyun@domain.elided

Thanks in advance.

Seunghyun Chung 
(Hoosier Chapter)

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