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Date:         Tue, 16 Apr 2002 17:44:43 -0700
Reply-To:     Brent Christensen <sbsyncro@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Brent Christensen <sbsyncro@HOTMAIL.COM>
Subject:      Great info: Vanagon head leaks and Fuel injection problems
Content-Type: text/plain; charset="iso-8859-1"

This is an e-mail sent to me at vanagon.com today. Christopher < cgoodwin@nomadiceye.com > raises some very interesting points about corrosion being related to broken ground straps. I know that this has been debated before on the lists, but I also felt his follow up information about the Idle Stabilzer could help a lot of people with the kinds of symptoms he describes.

And, yes - I did ask him to write the technical article, and when it is finished, we will post it to the articles section of www.vanagon.com ;-)

Brent Christensen

----- Original Message ----- From: Christopher Goodwin To: info@vanagon.com Sent: Tuesday, April 16, 2002 2:23 PM Subject: Vanagon head leaks and repair

Sir,

I have done quite a lot of Vanagon work in my 20+ years as a German car mechanic and have formed a theory regarding the head gasket issue as well as drivability.

The Wasserboxer frequently has drivability problems, most I have found are due to unskilled mechanics adjusting everything in sight without first going through the troubleshooting, if the problem has just begun, it is unlikely that randomly adjusting everything you can get your hands on will solve anything. Most adjustments do not simply go out of spec on their own and each thing you adjust is another thing which must be rechecked in order to locate the problem. One of the most common drivability problems I have found is caused by poor engine ground, a design fault of the Wasserboxer. This poor ground not only gives spurious feedback to the ECU from the various sensors (coolant temp, O2, etc) but also creates another problem which I believe is a direct cause of some head gasket failures.

The spark plugs fire by arcing from the input to ground, in this case the ground is the head, however the head is insulated from the case by the head gasket. If the grounds are not good then some of this electrical energy will obviously arc through the head gasket or at best be a cause of serious electrolytic reaction between the various metals and chemicals in the coolant. One solution I have found is the "Ground Net", a simple arrangement of wired and eyes connecting the heads to the case and the case to the body, in addition a small wire from the ECU to the body may be added.

Simply take some heavy gauge wire and solder AND crimp an appropriate electrical "eye" connector to the end, attach this eye to the cylinder head ground bolt and run it to the block at the distributor or any other handy place (be sure the distributor ground is also in place), attach another eye (solder and crimp) with another wire to lead to the other head, another eye for the head and another wire to the body, another eye, scrape enough paint for a GOOD connection and attach with a small bolt and nut then coat all the connections with battery terminal anti-corrosion spray and there you have it. The heads are grounded to the case and the case to the body, electricity will now take the path of least resistance and avoid the head gasket all together,

I have installed this "Net" on a dozen vanagons over the years and have had good results, it has solved several malicious drivability problems, given a brighter spark and as far as I know none of the equipped Vanagons have had head gasket issues. The only other home electrical repair I might suggest would be to seal, as best you can, the Idle Stabilizer Control Unit located behind the air intake cover, behind the right rear tail light, and to be sure it is mounted correctly in the upright position. This little unit looks like an inexpensive relay but is in fact a $260.00 (dealer) piece of electronic circuitry. When it gets wet and fails your idle will bounce erratically, may refuse to start cold or run hot, may idle at 1800-2500 rpm or die when coming to a stop or a host of other maladies.

The Idle Control Unit is something I have replaced on about 1/2 the Vanagons that come to me after they have been to every other shop in the state without solving the problems. They tend to be laying in the intake area and upon disassembly they are all corroded, one was actually full of water. I would love to find someone who could repair these little devils as even from my wholesaler they are $160 my cost. once they go out the Idle Stabilizer Valve will not function properly and my open all the way, not open at all, or do whatever it likes depending on mood and how badly you need to get where you are going.

The last Vanagon with this issue had bizarre symptoms: The Idle Control or Stabilizer Valve was disconnected, the engine would idle at 800 and die often when cold. Once warmed up it would run fine only occasionally dieing after running at high RPMs for a while (freeway off ramps), in addition the Van would seem to load up when going up mountain passes and quit, then start and run OK. If you plugged the Valve in the engine would race to 2000 rpm+. I checked the control unit by installing my good test unit and the duty cycle to the valve was then correct so I replaced it, everything was fine for about 5 minutes then it climbed to 2000 rpm again. I checked and the Idle Air Bypass screw had been turned all the way out to get the engine to idle without the valve connected, so the O2 sensor was feeding a lean condition signal to the ECU which would in turn richen the mixture, causing the engine to race to 2000 if at idle OR load up with fuel if being driven hard (up a mountain pass). Another example of someone making a problem worse with a Billy Backyard repair. The vehicle no gets better mileage, runs stronger, idles at 950, does not die or quit on passes.

In my experience the Idle Stabilizer system and the coolant temp sensor are responsible for 9/10 of Vanagon (Digifant) drivability problems. If you would like I can write a piece on how to make a VAG 1315A/2 test lead to check the duty cycle to the The Idle Stabilizer Valve. VW wants a fortune if they will get you one at all but they can be made from a few junk yard parts with ease.

I also have copies of the VW Pro-training manuals for Digifant fuel systems which outline all the tests and adjustments, these are in Adobe format and are easy to download and use, not to mention being invaluable!

Just my 2 cents.

Regards,

Christopher Goodwin Seattle, Wa.

© Christopher L. Goodwin NUJ IFJ 2001

www.nomadiceye.com

Author reserves all rights

National Union of Journalists 0894779

International Federation of Journalists GB 6831


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