I don't think the vacuum retard would have anything to do with idle emissions. The initial (idle) timing could be set anywhere VW wanted it. On my '85, neither vacuum advance or retard was affected at idle. (When I pulled them off and plugged the lines, the timing was the same as before.) The fact that the retard side pulls its vacuum source from a different spot should be a good clue. If I remember correctly, it gets its vacuum upstream of the throttle body, which tells me it has something to do with high speed emissions?. It would kick in when you get off the gas and retard the timing until you want to accelerate again? Anyone else want to take a stab at the vacuum retard purpose? Jay '85 Westy |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.