Date: Thu, 15 Jun 2000 13:08:49 -0400
Reply-To: "Carrington, Tom" <TCarrington@ReliTech.com>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Carrington, Tom" <TCarrington@ReliTech.com>
Subject: FW: Power Loss in rain
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-----Original Message-----
From: Joe Fahy [mailto:72510.1173@compuserve.com]
Sent: Thursday, June 15, 2000 7:03 AM
To: vanagon@gerry.vanagon.com
Subject: Power Loss in rain
I hope that someone has seen this before:
'87 auto Westy 2.1l loses power in rain or dense fog.
I can restore power by turning ignition key off then on when I lose power,
this only works for 10 to 15 seconds and then must be repeated. The tach
does not go to zero when the power loss is experienced, nor do I lose any
dash lights. This procedure is a little dangerous afterdark, not
recommended for distance travelling!
As soon as I am off of wet pavement, the van resumes proper operation.
From the symptoms and the Bentley wiring diagrams, I believed that a failure
of the left engine compartment ground, where the Digifant relay and the Fuel
pump are grounded was the most likely candidate. I still had a tach
reading, meaning that the coil was being triggered so I still had spark. So
this reinforced the loss of fuel possibility.
I have measured all grounds, except the ground lead from the Bosch ECU( I
have not found it yet), and all have been about 30 milliohms to the negative
terminal of the battery. I used a 4 wire technique, where both current and
voltage are coincidentally measured and the resistance computed. I then
sprayed all the grounds with water and the resistances went up about 10
milliohms. I do not think that this is significant. I may be wrong.
I then started the van and proceeded to 'hose her down' while it was running
to try and find the offending part- NO JOY! This included ALL electrical
sensors/components/connectors in the engine compartment, including both the
exposed (cover off)Digifant and fuel pump relays. I also sprayed the O2
sensor and it's connector and the fuel pump and it's connectors. The van
continued to run. Note the van was up to operating temp prior to spraying
with water.
With the sensitivity of the failure to water on the road, I thought that
almost any amount of liquid sprayed on the component/sensor would cause an
immediate failure, it has not.
I have 3 keys on my key ring and have played with the keys and the switch
while experiencing the power loss. While the ignition switch might be a
contributor, I can not make it cause the failure.
I have planned to get the Digitool before this started now it seems
imperative.
Can anyone offer some direction?