Date:         Mon, 7 Dec 1998 07:28:03 -0800
Reply-To:     Tom Young <young@SHERLOCK.SIMS.BERKELEY.EDU>
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Tom Young <young@SHERLOCK.SIMS.BERKELEY.EDU>
Subject:      Re: AFM Wear?
Comments: To: KBatzler <KBatzler@EMAIL.MSN.COM>
Comments: cc: vanagon@VANAGON.COM
In-Reply-To:  <008f01be2135$62debb60$36b4fdd0@karlbatz>
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Sun, 6 Dec 1998, KBatzler wrote:

> I noticed that the variable resistor
> is slowly wearing through the "carbon" track.  I know that this will
> eventually give me problems.  Is there anyway this can be repaired at home?

This problem has been discussed a lot over the years.  Two common fixes
have been mentioned: 1) Slightly bend the wiper arm so it sweeps over a
different track and, 2) (the better fix by my logic) remove the board all
together, then slightly enlarge or "slot" the holes in the board through
which the attaching screws pass and reposition the board slightly.

> I noticed that the resistor board is glued in place.  Is there a source for
> these?

Not that I'm aware of.

> PO was "playing" with the spring tension and have had to increase it
> 4 notches to run correctly.  Are there any procedures to check this at
> home???  Maybe with the O2 sensor output?

Yes.  Disconnect the O2 sensor (with the engine off) on a completely
warmed-up engine.  Attach a digital voltmeter to the sensor and restart
the engine.  Set the mixture, using the adjustment screw and/or spring
tension, until the voltmeter reads approximately .5 volts; it won't read
a steady .5, but should flip above and below .5 for an "average" of
around .5 volts.

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Tom Young               young@sherlock.SIMS.Berkeley.EDU
Lafayette, CA  94549    '81 Vanagon
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