Jeff, I would check all your ground connections (look on driver's side head),
and then check all of your vacuum lines.  If these are OK, it is possible
that your idle stabilizer could be going bad.
I have new idle stabilizers for the 1.9l Vanagon available for $24 if you
find you need one.  These are normally $150 from the dealer.

Thanks,
Ken Wilford
http://www.vanagain.com
John 3:16
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