Date: Sun, 22 Jul 2007 22:57:14 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Vapor lock? Static electricity? Help!
In-Reply-To: <000801c7cca2$264eb890$72ec29b0$@net>
Content-Type: text/plain; charset="iso-8859-1"
If you can hear the pump changing pitch, then most likely you have a bad
pump that is being effected by heat. The CIS system re-circulates a lot of
fuel and will eventually heat up the fuel in the tank. If you are vapor
locking, it is happening on the suction side. This is why a number of CIS
have a second pump inside the tank to transfer fuel to the inlet of the
main pump under pressure. This is common on late Fox, Golf, Jettas.
Mercedes even used a fuel cooler that used the low pressure side of the AC
to cool the fuel as it entered the fuel distributor.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Paul Chubbuck
Sent: Sunday, July 22, 2007 4:52 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Vapor lock? Static electricity? Help!
Mine is a 1982 Vanagon, originally diesel with a conversion to a rabbit
engine from about 1985.
Do these symptoms ring a familiar bell to someone knowledgeable on this
list?
Last Wednesday I took off at 3 PM intending to drive about 500 miles. It
was about 100 degrees out. After a short time, I noticed a frequent,
partial loss of power, much as if I had suddenly backed my foot partway
off
the accelerator. When I had to stop, the engine died unless I kept the
engine RPM's up. Both problems became worse, so I limped my way back 35
miles to my mechanic right at quitting time. I also noticed that when
stopped and holding the engine above normal idle (to avoid stalling) that
I
could hear the fuel pump cycling every few seconds between high and low
rpm.
When it reached the low end of the cycle, the engine would almost stall,
and
then pick up again as the fuel pump took off.
I suspected a bad fuel pump but my mechanic wasn't convinced it was so
simple and I'm not a mechanic. The next day was cooler and he has so far
not been able to repeat the problem.
A VW mechanic friend told me about a static electricity problem with this
engine series that might cause such symptoms and could be corrected with
some kind of an adaptor. I found a reference to this problem in the
archives, although not much detail. My friend also thought that the high
temperatures could be causing vapor lock. If it's that, I don't know how
to
confirm or resolve it.
I should say that I first noticed this unsteady power problem more than a
month ago, but then it was infrequent and subtle, so I let it go. But
last
Wednesday it wasn't sure I was going to be able to make it home, never
mind
my intended trip across the hot plains of Eastern Colorado and Kansas.
I appreciate any help.
Thanks,
Paul in Fort Collins
