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318I IDLE CONTROL VALVE BLUES

My husband finally got the 318 going again.  And I finally got him to write down 
what he did...

FYI,
Pamela
thomas@domain.elided
84 318 & 70 2000A

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I have never purported to be a mechanic/expert, but I have been driving BMWs for 
about 10 years.  I have a 1984 318i and a 1970 2000 automatic (not 2002), and 
have had a 1984 533i as well.  I have shop manuals for these cars, and have 
performed most of the repairs on my vehicles, except when I didn't have the 
proper tools, space or time.  I am referring to the piece written by Tom Walter 
of Beaverton OR, and I am grateful for the information and insights that were 
provided.

There was a statement in the ICU Overview which said that the Bentley shop 
manual suggested that the adjustment screw on the idle control valve does not 
increase the idle speed, and I agree with Tom and not with Bentley that it most 
certainly does increase the idle speed.

The problems started when the car would idle very high (2500-3000), and I 
couldn't get it under control.  A mechanic with whom I used to deal with 
introduced a "kludge" which consisted of pinching off part of the inlet hose 
with a clamp, until the idle was correct.
This worked for about eight months (11000 miles).  After this time, the car 
wouldn't hold an idle at all, and kept cutting off.

I followed the diagnostic procedures outlined in Tom's article, and for the most 
part, was getting correct readings.  I was baffled because the car still 
wouldn't idle.  I decided to take apart the Idle Control Module, whose case is 
olive green in color, and is located in the upper left-hand side of the glove 
compartment, forward of the DME (digital motor electronics) box.  I inspected 
the interior of the unit, and observed that one of the components was obvoiusly 
burned out.  This component, a resistor, was located at the edge on one of the 
boards inside.  This resistor was originally grey in color, (now a fried black) 
and was only stamped "56R 10%". I assumed this to be a 56 ohm resistor with a 
10% tolerance.  It did not conform to the striped standard resistors which one 
may find at Radio Shack.  No one at any of the Radio Shacks I went to in Raleigh 
NC knew what I was talking about.  I wondered how a person could get a job in an 
electronic parts store, and be unaware about electronic parts.

My wife, who is an engineer, secured a replacement resistor for me.  She got me 
a Dale type resistor, 56.2 ohms, with a 1%tolerance, part number T1 68 21.  It 
was the closest she was able to get.  I dusted off the ol' soldering iron, took 
the fried component out, and put the new one in, and re-installed the Idle 
Control Module.  When the car still refused to hold an idle regularly, I decided 
to replace the idle control valve.  All dealers were quoting me $207.77.  I got 
in touch with KSK, of San Jose, CA (1-800-624-5888) and obtained a new idle 
control valve at a BIG discount.  Let me just say that I saved lots of money!!!  
When the new part arrived (next day air) I installed it, and all was just 
peachy.  She still idles a little higher than normal (1200-1500 rpm) but she 
runs great!  Let me add that I bought this 318i new, and it has 215,913 miles on 
it, and I have been very, very hard on it.  Let me further add that I have not 
replaced the oxygen sensor, ever.  I know that it should've been replaced every 
50,000 miles, but didn't do it.  We'll see if the idle becomes more in the 
normal range once the oxygen sensor is replaced.  Should any of you need a Idle 
Control Module, talk to the people at ProgRama in Boca Raton, FL (407) 338-8447.
- --Keith Roy Thomas, Raleigh NC

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