Date:         Tue, 25 Jan 2011 00:06:31 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: 85 Vangon revs drops, revs drops, revs drops,
              and then dies after a few minutes of this cycle
Comments: To: Mark Carrig <stratmanx@YAHOO.COM>
Content-Type: text/plain; charset="us-ascii"; format=flowed

>If the old AFM doesn't cure it, peel back the boot on the plug and
>back probe the terminals, counting one as the leftmost.  Ignition
>on, you should have +5 on pin 3, +5 between pins 3 and 4.  If those
>are good, open the air box so you can get to the vane and move it.

Forgot to say, if either of the above tests are bad, you have an open
connection between there and the ECU, or a bad ECU.  The +5 comes
from pin 19 and the ground from pin 6 at the ECU.

Also forgot to say that if you have the VW-syndrome dongle attached
to the AFM wire, you have to remove it before making these
tests.  It's also conceivable that the dongle itself could be causing
a problem, though I've not heard of one doing so.  If you have the
capacitor fix that should not change anything.


>  Measure from pin 2 to 3 (with an analog meter if available) and
> slowly move the vane.  You should see voltage change smoothly from
> 0-5 volts (or 5-0, I forget which way it goes).  If yes, shut off
> ignition and check for zero ohms between pin two and ECU connector
> pin 15.  If ok, find a working ECU to trial-swap.
>
>Yours,
>David