Date:         Tue, 7 Oct 2014 13:23:42 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Checking vacuum diaphragm was Re: Looking for a 83-85 distributor
Comments: To: Ryan Perry <rjdperry@GMAIL.COM>
In-Reply-To:  <CAKLYf10r0ScKsoJKkdC2KjngbaBKVF4HEYMUGKJpkaBFmS9JLQ@mail.g
              mail.com>
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At 11:31 AM 10/6/2014, Ryan Perry wrote:
>Excuse the unknowing question and possible thread jack but how do you check
>the vacuum advance? I have an 84 with a terrible time taking off...I have
>to rev and get throttle up for it to go or it just sits there hesitating.
>wondering if this might be my issue as well?

The 1.9l distributor has centrifugal advance and vacuum diaphragm
mechanisms for both advance and retard. I'm sure Bentley has specs
for degrees of change vs amount of vacuum, but to check that they
work, pop the top off the distributor.  Pull the vacuum lines off the
advance mechanisms and using a spare piece of tubing suck on each one
and watch for movement of the rotor.  It should rotate as you suck,
come to a hard stop at some point, and smoothly return to a stable
neutral point as you gradually allow air back into the tubing.  One
should cause clockwise and the other anticlockwise rotation.

The centrifugal advance is operated by a pair of spring-loaded
weights inside the distributor body.  I don't think you can directly
check them with the distributor in place (but they're affected only by rpm).

While you have the top off put a few drops of oil into the felt in
the top of the distributor shaft, under the rotor.

Yours,
David