Date: Thu, 27 Jun 1996 11:42:03 -0400
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: cp682@cleveland.freenet.edu (Lisa Quinn)
Subject: Fuel pump relay problem solved!
Thanks again to all that sent me information about the fuel pump relay and
its location. Well we spent a night with the Bently manual wiring diagram
in hand, and a voltmeter. Using the test procedure for the ignition control
module, we found out that most things checked out ok. The fuel pump was only
getting current when the starter was energized, as soon as the key is
released from the start position, no current. This confirmed our suspisions
about the double relay. Also realized that the fuel pump shouldn't be
getting any current with the key on, but the engine not running. So checking
continuity of the wiring, nailed it down to that relay. Well after finally
getting the relay off, Bob took it inside to look at it. He's an engineer,
and had to see how the bugger works. He brought in a 12V power supply, the
wiring digram, and started to play with it. After about an hour of playing,
he called me over showed me the problem. One of the contacts on relay one
had come unsoldered after all of these years. The starter energizes the
first relay, and when the starter goes off, the coil energizes the second
relay. But the whole sequence goes awry if no current gets to the first
relay. The only reason we could start up was because the vibration of the
engine and starter were giggling the loose connection enough to get some
current into the relay. As soon as the starter stopped, that relay would
open, and the fuel pump would die. A drop of solder fixed the double
relay! Then Bob figured out why the starter was getting current when the
key was on but the engine not running. It has to do with the air mass
sensor by the air filter. Pop the top off the sensor, and if it is working
correctly, when the sensor is at the no air flow position the lever will
open a contact up by pressing on a bar. On our sensor, the bar had snapped
off before we bought the van. Bob soldered a piece of wire onto what was
left of the bar to extend it, and now it works as good as new. With a little
persistence, we fixed the van without spending a dime. And that was really
cool!
Lisa
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Lisa Quinn at cp682@cleveland.freenet.edu
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