Excellent information.  Cheers, Bruce

>After many, many hours of fruitless troubleshooting, parts swapping,
>cursing, poking voltmeters into circuits, etc. I finally found the reason
>why my 87 syncro would run rich no matter what I did or what I replaced.
>Gerald Skerblitz, our former listmaster, pointed out that the oxygen sensor
>wire was coaxial in nature- it is a layer of green  plastic insulation over
>a grounded wire sheath, over another green insulation layer, with the wire
>that carries the small (0-0.9v) oxygen sensor current in the center.  Some
>long-ago mechanic had replaced the spade connector by simply crimping a new
>one on, and had both the grounded sheath and the center wire under the
>connector, effectively grounding out the oxygen sensor circuit, regardless
>of whether the sensor was connected or not.  While I have directed many an
>expletive at this unknown person, that actually was an easy mistake to
>make-it takes a careful examination to discern that this particular wire is
>different than most of the others in the system.   This apparently makes
>the ecu dump in more and more fuel, causing the symptoms I described in my
>previous post.  Simply cutting back the grounded sheath half an inch and
>crimping a new connector to the central wire solved the problem- the van
>immediatly started running great, in spite of low compression in a couple
>of cylinders.  Small things are so important with these systems!  Special
>thanks to Gerry and to the many other people who pointed out a whole slew
>of facts I didn't know about the digifant fi.
>
>Bill
>www.geocities.com/yosemite/gorge/1706
>

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Bruce Ralphs, Victoria, BC                 '85 Westy, auto, 142K
250-727-7617                               '91 Passat, 95K
250-727-7685 fax                           '83 GTI,  256K