I had a very similar problem with an 82 air-cooled Vanagon which shares
some electrical similarities with your vehicle. The problem was
eventually solved after a) the idle stabilizer was replaced and b) the
pipe running from the aux. air regulator to the intake was replaced. It
could be something different in your case. You can run your car with the idle
stabilizer bypassed (connecting the links together-check the manual first!) to
check on that potential
area. If none of your hoses look in bad shape test your a) air regulator
and b) test for vacuum leaks. There is (was) a FAQ on this in the Vanagon
gopher - Good luck - DC -- 

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David Carment
School of International Affairs
Carleton University
Ottawa, Ontario
K1S 5B6
voice - (613) 788-2600-6662
fax - (613) 788-9882
Email address: dcarment@ccs.carleton.ca
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