My 91 did the same thing.  Turned out to be the throttle position switch was
out of adjustment and wasn't indicating closed throttle.  When I'd tap the
pedal, it would be just enough to trigger the switch.  Took a while to
adjust as my throttle body is old and worn so exact adjustments are not
really possible.  Easy to check, just pull the plug off and check for
continuity when the throttle is closed.  Open the throttle by hand and let
it close slowly and see if the switch closes again.

Just my experience.  Good Luck

BC

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Zeitgeist
Sent: Friday, July 19, 2013 5:06 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Idle Control Issues

I like air conditioning; I like it a lot.  When I drive, I drive with the AC
on.  That's just how I roll.

So, the problem for me is that the 2.1L WBX wants to idle at 2k with the AC
on.  Doesn't do it with the AC switched off.  I usually just blip the
throttle and it settles down again, but this is getting to be quite annoying
and possibly not entirely good for my ongoing health.  It's always done this
intermittently to some extent, but now it's really pronounced and
super-double-extramittent.  Can I assume the idle air control valve is
"sticking", or is this more likely an idle relay issue?  I know Audis have
an idle control valve that can be taken apart and lubed up when they stick,
but these appear to be factory sealed from prying eyes and hands.  The van
is getting a TDI swap in the near future, but I would like to continue
driving it in the meantime.  What say ye gurus?

--
Casey