Sincere thanks to Ken, Charlie, Eric and John (did I forget anyone?) for the
diagnostic tips to solve my weird cyclic idle problem that no mechanic in
our one-horse-town �Juneau, Alaska has been able to solve.  My guess is the
advice from the Vanagon list will again bail me out like so many times
before.  Next week I move the van into the garage and start going
methodically through the lists.  I will report back. Thanks, Jeff

1986 Vanagon
With AST conversion

>From: John Rodgers <jh_rodgers@bellsouth.net>
>To: Jeff Hartman <jeffhartman11@HOTMAIL.COM>
>CC: vanagon@GERRY.VANAGON.COM
>Subject: Re: 86 Vanagon unstable idle
>Date: Thu, 01 Apr 2004 09:45:23 -0600
>
>Jeff, I had a problem with erratic idle on my 88 GL, as you describe. With
>the engine warm, I disconnected the idle stabilizer valve and the erratic
>idle stabilized. Supposedly the idle stabilizer is cut out of the circuit
>when the engine warms up, but if there is a fault in the idle stabilizer
>circuit - either the ISV(up on top of the engine or the Idle Stabilizer
>Control (ISC) - a black box located just forward of the right hand brake
>light (remove the tail light for access)- this erratic idle can occur.
>
>If this is the source of the problem, you can drive quite safely with it
>disconnected until you can get the right repair.
>
>The idle stabilizer circuit does three things.
>1) Kicks up the idle until warm-up after a cold start
>2) Kicks up the engine RPM to avoid stalling when the power steering turn
>limits are reached ant the power steering pump is loaded.
>3) Kicks up the RPM to avoid stalling at stoplights, etc, in traffic, when
>the air conditioner cycles on and off.
>
>Good Luck.
>
>John Rodgers
>88 GL Driver
>Jeff Hartman wrote:
>
>>Hi, I have been struggling with an unstable idle. It is very cyclic and
>>the
>>cycles and frequency increase with an electric load (fans etc.) With the
>>O2
>>sensor and temp sensor replaced, and other tuneup adjustments made, the VW
>>dealership claims I need a mass airflow sensor. This was determined
>>without
>>any computer diagnostics. In fact the dealer's service department says
>>that
>>their new computer testing equipment no longer can test our obsolete
>>Vanagons.
>>
>>I don't have a lot of faith in them, so do you have any ideas of whether
>>they are right and what I should test next? I made a cursory review of the
>>archives over a couple of recent years, without finding this exact problem
>>described.
>>Thanks, Jeff Hartman
>>Juneau, Alaska
>>86 2.1 Vanagon
>>
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>

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