---------------------------
Hi Larry and Volks,
    I  maybe should not have been quite so harsh in explaining the path
electrons must take to complete the circuit on the oxygen sensor and  VW did
a pretty good job as many of our vans have over 200k miles.  Keep in mind
many of us have never had trouble with the grounds.  The most probable point
of failure would be the connection on top of the left head. If we soldered a
wire to the ECU cable wire that goes to pin 19 and use a ring type connector
under a ground screw on the head should be adequate.  Cleaning the connector
on top of the left head will work also for a time. Maybe it is all the
vibration that cause the problems with the ground connections on top of the
engine.
    Your idea of running a wire from the sensor to head would eliminate many
points of failure.  I would consider running it from the sensor to the ECU
pin 19 wire on top of the left head.
    I  have never tried a 4 wire  oxygen sensor on the wasser boxer but I
plan to the next time I replace mine.  They have the white heater wires and
the black just like the 3 wire sensor. They also have a gray wire that is
the minus lead from the sensor to the ECU.  We could connect  this gray wire
to the wire on the left head that goes ECU pin 19.  If this works out I'll
check into the possibility of getting a 4 wire connector that mates up to a
popular low priced 4 wire O2 sensor.  Then we will only need to solder
connectors on one time.

Darrell

-----Original Message-----
From: Lawrence Johnson <ljohnson@HALHINET.ON.CA>
To: Vanagon@VANAGON.COM <Vanagon@VANAGON.COM>
Date: Friday, August 14, 1998 7:27 PM
Subject: Re: 87 Vanagon hesitation chapter (3)

>Darrell,
>Would a ground strap from the Oxygen Sensor to the left engine head improve
the
>OS ground path to the ECU?
>
>Darrell Boehler wrote:
>
>> This looks  more like an ECU all the time.  There is one wire from the
>> ECU pin 19  to the  left engine head. Measure this wire to make certain
it
>> is good.  It provides the ground path for ECU O2 sensor circuit. <snip>
>