Date:         Wed, 25 Jun 2014 09:24:09 -0700
Reply-To:     Don Hanson <dhanson928@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Don Hanson <dhanson928@GMAIL.COM>
Subject:      Re: Inconsistent stumbling on resume throttle..Was "vanagon
              syndrome?"
In-Reply-To:  <BAY406-EAS577BE851D7DC43C713901DA0190@phx.gbl>
Content-Type: text/plain; charset=UTF-8

 more...I may have the culprit...

  I removed my O2 sensor, which was a Denso Universal..It was adapted, with
the Denso junction plug.... into a long flat VW plug on the motor end of
the harness...4 prongs...3 from the O2 sensor to the brain and one (grey)
from the harness plug to a ground nearby.
  Of the three coming FROM the O2 sensor (two white, one black) the black
lead was almost completely broken...or maybe it was and just touching now
and again...   So that may have been the problem, certainly it was not
functioning properly in that condition..
    The O2 sensor itself:   It looks pretty strange in that it was covered
with soot, most likely from idling while the exhaust warmed up to get it
removed, but under that  thin soot, there was a thick caked white deposit
covering the whole element...I don't know what these are supposed to look
like but that doesn't seem right.

  So I have a new Bosch sensor..two whites and a blue with a round plug...I
am going to splice that into the VW flat plug...putting the blue to the
black and the white to white...the grey will go back to the block where it
was before.
  The Bosch sensor is different in that it has a perforated cylinder
covering the element, I guess..but I think I got it as a specific VW
sensor...

   I also found in my parts collection a good Temp II sensor (tested as per
the Bently) a new red Bosch coil and an underneath throttle switch...(I
think..on the inline VW motor the switch is 'concealed' below the throttle
body...

   I am first going to change the O2 sensor and the Temp II sensor, see if
that does it...

  Anyone have any comments?

On Wed, Jun 25, 2014 at 12:08 AM, Dennis Haynes <d23haynes57@hotmail.com>
wrote:
The symptoms clearing after cycling the ignition switch is classic of a
problem with the O2 sensor or circuit. Sensors do get intermittent and they
are easily fouled by road stuff on the outside and worse oil or antifreeze
on the inside. Rich mixtures for any reason can also cause them to carbon
foul.
On the Vanagon Digifant another common problem is a bad ground for the O2
reference circuit. One of these connections is the ground wire in the
harness to the distributor. Check the archives. I have written the
procedure to test the O2 sensor wiring in the past. If it can’t be found I
can re-write.

Dennis