It's an electromagnetic (correct term?) valve. As input power varies,
so does valve position and amount of air it allows to bypass into the
intake plenum. Under certain conditions (i.e. added loads, AC, PS),
the valve opens more to allow more "bypass" air into intake to keep
the idle more or less at spec. AFAIK, there's no serviceable parts
beyond cleaning it with throttle cleaner (and maybe MAF cleaner too?).
i don't think you can easily take it apart. Once the coil or mechanics
are toast, that's it. I've often wondered if a Mk3 Jetta/Golf etc ISV
could be used in a WBX 2.1  (the ISV is pricey new?)

Ironically, my first google took me to to a Vanagon valve etc. image here:

http://ww2.justanswer.com/uploads/bry8ntph8m/2009-12-22_023755_86VanagonIdleStabilizationValve.jpg

A diagram of an ISV for an Audi but appears to be same or similar to
the Vanagon 2.1 part:  http://20v.org/isv2.gif

On Sat, Jul 20, 2013 at 10:24 AM, JRodgers <jrodgers113@gmail.com> wrote:

> What  about that ISV? Has anyone ever had one apart to see how it works?
> Can it be disassembled cleaned and re-assembled?> Adjusted in any way? I
> too have stabilizer issues.
>
>
> John
>
> On 7/20/2013 10:23 AM, John Meeks wrote:
>>
>> FWIW, when I was having a runaway idle issue I cleaned and lubed the idle
>> control valve. Carb cleaner followed by a short shot of wd40, engine
>> running.

--
Neil n

Blog: tubaneil.blogspot.ca

'88 Westy http://tinyurl.com/c8rlw6p

'81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/

Vanagon VAG Gas inline-VR Engine Swap Group:

http://tinyurl.com/d7gd5ej