Greeting Listmembers,

I would like to politely suggest that attempting to correct any problem
with the running of the engine while leaving the O2 sensor connected is
flatley incorrect.  Disconnecting the O2 sensor should be the first
step.  If the engine still runs poor, find the problem.  If the engine
runs perfect, then and only then correct the the O2 sensor faults,
either a shorted cable, or a dirty or faulty sensor.  The sensor can be
mounted in a vise, apply a propane touch to clean the end of soot and
return to service. Try this first before replacing the O2 sensor.
 Connect a digital volt meter to the black wire, other lead to the body
of the sensor and look for voltage as you heat it up. Should reliably
reach .8 volts and then drop as the flame is remove.

So  eliminate the  O2 signal first, and after all other repairs are
accomplised, then re-connect the O2 sensor.

I say this because the basic Bosch Fuel injection will allow the engine
to run perfectly without the O2 connected.  If the engine doesn't then
the basic fuel injection needs to adjusted or repair, generally just an
adjustment.  The O2 sensor is only there to keep a finely tuned fuel
injection within limits, not to compesated for a maladjusted systems.
 With the age and milage on the systems we need to learn how to adjust
them.

I and others have written about this.  You can search the archives
http://gerry.vanagon.com/cgi-bin/wa.exe?S1=vanagon with kelphoto as part
of the author's email address for detailed instructions.

Happy tuning,

Sincerely,

Mark Keller
91 Vanagon