Date:         Tue, 29 Feb 2000 09:14:39 -0500
Reply-To:     Woody Halsey <WoodyHalsey@COMPUSERVE.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Woody Halsey <WoodyHalsey@COMPUSERVE.COM>
Subject:      Woody's wiring problems solved, he hopes
Content-Type: text/plain; charset=ISO-8859-1

Dear List,

Some of you will recall that I have been struggling with weird performance
symptoms since last summer. Though I still have other problems (cf. post re
exhaust) I think I have finally got the engine running the way it used to

and should. Unfortunately, since I have replaced so many components and
didn't have the skills or time to do it as systematically as Doktor Tim and
others recommend, I am still not sure that I pinpointeda single culprit,
but most likely there were two or three. In any case,  here's what I've
done, and learned.

1) Replaced the exhaust system and the coolant pipes with new parts from BD
and dealer. No impact on FI problem and expensive, but necessary and I am

glad I did.
2) New Temp2 sensor. Not sure if it helped, but certainly a good idea. Also
new O2 sensor; it was time.
3) New fuel pressure regulator. Probably not necessary, but no harm done
and may avoid problems years down the road.
4) Added the VW "cap fix." Ditto.
5) New fuel filter. Ditto.
6) Added ground wires to ECU and AFM. Not sure if it helped, but certainly
a good idea.
7) Changed the switches on the throttle. Definitely eliminated the
floor-it-no-response syndrome at stop signs. Will keep spares on hand.
8) Added new main ground strap and cleaned all other ground connectors.
Obviously key.

And, finally, my mechanic replaced the whole FI wiring harness with a very
good used one which Robert Keezer had picked out for me. (Thanks again,
Robert!). That seemed to clear up the erratic electrical signals I was
picking up on the Digitool (Thanks again, Darrell Boehler!), particularly

from the O2 sensor. Also, we discovered a leak in a vacuum hose when the
old harness was off. I had previously checked for vacuum leaks with by
spraying starter fluid around when the engine was running, as suggested by
a list member, but had turned up nothing.

Mysteriously, the good harness also seemed to make the clock work (post
hoc, ergo propter hoc fallacy perhaps?).

I drove 240 miles watching the Digitool like a hawk and all seemed normal

-- no surging or bucking, decent power and about 20MPG. So, I concluded
that there had been a hidden break or short somewhere in the maze of wires
of the old harness and that the replacement had solved the problem.

I put away the ECU that is attached to the Digitool and put the ECU from my
late not-lamented parts van back in place. Guess what? The beast again
began bucking at 20, 35, 50 MPH!!! With every other element in the system

apparently working properly, I concluded that that ECU must have been
squirrely all along -- even though it seemed at times to work well and even
though Darrell had checked it out. In other words, there must be something
loose in it. Sometimes she works, sometimes she doesn't. S-o-o-o .... I
popped in yet another ECU (thanks yet again to Robert Keezer) and ...
everything seems to work properly ... for now. I've only drive a few miles
and will ned to wait 'til next week to get the exhaust bolted back on. Then
I can do a long drive or two to make sure my sense of relief is not
premature.

Moral of the story: Be patient, replace everything, and thank your lucky
stars that The List is there to help you out!

Woody