Date:         Thu, 24 Jun 1999 11:42:30 -0500
Reply-To:     cdo9@CSI.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Cliff Ober <cdo9@CSI.COM>
Subject:      Re: On the road again!!!!
Content-Type: text/plain; charset="iso-8859-1"

-----Original Message-----
From: Cliff Ober [mailto:cdo9@csi.com]
Sent: Thursday, June 24, 1999 10:14 AM
To: 'Woody Halsey'
Subject: RE: On the road again!!!!


Hi Woody,

A capacitor (also known as a "cap") is a two leaded electronic component
which opposes any change of voltage between the leads. It can be used to
smooth out a pulsating voltage like is sometimes produced by the AFM on our
vanagons in response to the intake of air to the cylinders. The ECU can
sometimes be confused by the pulsation, so VW came up with the $100 harness
addition to the AFM. The harness has nothing but a couple of connectors to
add a capacitor to the circuit, and pass on the signals from the AFM.

You, (or your mechanic) can add the cap to the AFM wire harness for about 50
cents plus the time to solder it in place. A good place to insert it is
inside the rubber boot of the connector that mates with the AFM. The boot
can be rolled back to provide working room. Contacts 2 and 4 of the
connector can be released and pulled out far enough to solder the cap's
leads to the back of the contacts, which are then re-inserted in the
connector body. The boot can then be rolled back up over the cap and onto
the connector. Releasing the connector contacts is done by inserting a small
pin (I used a tiny jeweler's screwdriver) into the front of the connector to
depress a small barb which retains the contact (the barb should be bent back
out slightly after release to make sure it catches when the contact is
re-inserted).

The capacitor can be obtained from Radio Shack. It should be a tantalum type
with a value of 22 microfarads, and a voltage rating of 25 volts or higher.
This type of capacitor has a polarity to it that will be marked with a plus
sign, dot, or some feature to mark the positive terminal. The cap's positive
terminal should be attached to the AFM connector contact #2.

For what it's worth, this modification did not have any effect on my
"stumbling" problem - I'm still looking...

I'm going to post this reply to the list as well as to you privately so that
others may benefit, and so that just in case I've erred somewhere in this,
it will be corrected. Keep an eye out there for other responses.

Cliff

-----Original Message-----
From: Woody Halsey [mailto:WoodyHalsey@compuserve.com]
Sent: Wednesday, June 23, 1999 7:01 PM
To: INTERNET:cdo9@CSI.COM
Subject: On the road again!!!!


Dear Cliff,

I was struck by your reference to "stumbling" problems, since that is
precisely what I have experienced with my '83 Vanagon. Usually just
briefly, and at 30 and/or 50 MPH. I have recently exchanged my ECU and AFM,
installing used parts. Any thoughts? What is a capacitor and what does it
do? I am clueless, but could get my mechanic to put one on, if it would
make my engine run more smoothly.

Thanks,

Woody Halsey
'83 Vanagon
'64 Bug
'89 diesel Jetta (this one runs reliably!)