At 02:11 PM 9/9/98 -0500, Budd Premack wrote:
>I have the same 2000 rpm idle that Mark Schrope had (List posting 7-23-98)
>when I switch on my a/c.  Has it been determined that the cause is the idle
>stabilizer contol unit (by the right tail light) failing to properly close
>on idle?
snip
>
>Is there any other reasonable cause beyond the idle stabilizer control
>unit?
>If this is the prime suspect, is replacement the only option?
>
>TIA for everyone's help.
>
>Budd Premack
>86 Syncro, 73 Super
>Minneapolis, MN (Land of Sky-Blue Waters)
>

Budd,
I found a post from Jim Davis from about a year ago where he details taking
the unit apart and replacing the bad components. I haven't tried this, but
it sounds like it worked for him.
here is the post,
Don Kane

>----
>Recently I related the story of my 87 Syncro suddenly developing a +4,400 RPM
>idle.  I traced this to the Idle Control Module located forward of the
>right/rear taillight.  The dealer said list was $208.  I called several
>wreckers and was quoted from $80 to $20 for this item.  I bought the $20 one
>and it arrived yesterday.
>
>Meanwhile I was pursuing repairing the bad module.  Inside the module I
>discovered two components that were suspect.  The first one, a voltage
>stabilizer transistor was definitely fried.  I found (from my 88 Vanagon
>module) a company logo: SGS in tall narrow letters pushed up against
>eachother & other numbers were BD 438 and 9  741.  I found that an ECG or NTE
>185 was a replacement component for it.  The other component was a rectifier
>diode that had some signs of being overheated but was not overtly fried as
>the other component had been.  The diode had the numbers  GP15G-7001 and GI
>   8641.  I thingk the GI is for General Instruments.  Well, found that it
>could be replaced with an NTE 125 or ECG 125.
>
>Yesterday, I installed the two new components and the bottom line is that
>after poping the module back in, my van idles normally again!  :)
>
>Cost?
>NTE185:   $2.25
>NTE125:     $.88
>
>Total:       $3.13 + tax
>
>Compared to dealer list, I saved about $205. - that's 98.5% less!!  :)   :)
>  :)
>So now I've gone from needing a new module to having a spare for future use.
>:)
>
>Jim Davis
>87 GL Syncro
>88 GL Wolfsburg
>