O2 Sensor circuit problem!

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Eric Unrau
Sent: Wednesday, September 21, 2005 1:33 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Losing power...

Hello all,

For the last week I have been experiencing a random loss of power in my
'89 Westy.  Everything will seem normal as I am driving along, and then
suddenly the power will drop off to about 40-50%.

The first time it happened, I pulled over the side of the road, shut the
engine off and checked all the connectors at the plugs, coil,
distributor, Hall sender, etc.  I didn't find anything that was
noticeably loose but when I got back in the van it started up fine, so I
though I might have pushed a wire into place that wasn't obviously
loose.

I continued driving and 10 minutes later the power drops off again.
This time I pulled over and left the engine running/sputtering; checked
the wires again and when I gently jiggled the connector on the Hall
sender (it hangs somewhat loosely off the side of the distributor) I
heard a buzzing sound (short cct?) and the engine stalled.  Started it
up again, sounded fine so I drove off - again all seemed normal.  This
happened a couple more times over the next 30 minutes of driving (did I
mention my unhappy passenger/wife is 9 months + 2days pregnant?) and I
continued to look for loose wires each time - and managed to stall the
engine each time I wiggled the connection to the hall sender.

Assuming that the loose hall sender connection was the problem, the
following day I wrapped 14 gauge wire around the distributor to
immobilize the hall sender connector and then took it out for a test
drive.  All seemed good for the first five minutes or so until the power
dropped off - apparently my brilliant fix wasn't so smart.  This time I
was rolling along on a quiet street an it dawned on me that normal power
always seems to be there when the engine is started, so I gave it a try.
I shut the ignition off for 2 seconds and restarted as I was rolling
along the street and sure enough the engine seemed to be running
normally again.  As I continued driving I experienced a couple more
power loss cycles that were corrected immediately be turning the
ignition off and restarting the engine.

Any and all suggestions on a diagnosis of this problem are welcome.  The
Hall sender connector has been hanging off the side of the distributor
since I purchased the van from the PO but has never caused this problem
in the past.  Probably should replace it to eliminate it as a
possibility, but if it is something else.

Thanks

Eric

---------------------------------
Find your next car at Yahoo! Canada Autos