Date:         Wed, 26 Aug 1998 11:48:08 -0900
Reply-To:     Steven Johnson <afslj1@UAA.ALASKA.EDU>
Sender:       Vanagon Mailing List <Vanagon@vanagon.com>
From:         Steven Johnson <afslj1@UAA.ALASKA.EDU>
Organization: University of Alaska Anchorage
Subject:      O2 Sensor Questions
Comments: To: vanagon@vanagon.com
Content-type: text/plain; charset=us-ascii

Greetings listees:

I can hear what you're saying: "not another O2 sensor post!"  But bear
with me.  I've tried to search the archives, but for some reason I keep
failing.

This has been an ongoing problem with my '87 Westy: I'll be driving down
the road, van will suddenly lose power.  It will idle, roughly, but will
not accelerate.  When I turn off the key, something "resets" and the van
runs fine for a minute or two, but then will lose power and run roughly
again.  Clearly a fuel supply problem, but why?

Things done:

1. new fuel pump and filter
2. another new fuel filter
3. auxiliary wiring harness for AFM installed

After each of these "fixes," the van runs fine for a while (not a set
period of time, just "a while.")  In fact, after the aux. wiring harness
for the AFM I thought the problem was solved; no stutters for over 2000
miles.  But, on my way to catch monster Alaskan rainbow trout last
weekend, the same thing happens.

So I (reluctantly) take it to my VW dealer (prior to this, I'd been
dealing with my trusted local mechanic).  Keep in mind that part of the
problem is that, even without a "fix", the problem goes away, so the van
is essentially running normally when I take it to a mechanic (i.e. after
the stumbles this weekend, the van has run fine).

The dealer mech interrupts me halfway through my explanation of symptoms
and says "...and if you shut it off and start it up again it runs fine
for about a minute or two?"

"YES!!" I respond, elated that someone is familiar with the problem.

"It's your O2 sensor," says the dealer mech.

So here are my questions:

1. Is the O2 sensor that cylindrical object stuck into the end of the
catalytic converter?

2. Where do you unplug it to replace it?  I've traced the wired into the
engine compartment and found what looks like a plug junction, but
couldn't seperate the wires.

3. Can you run the engine without the O2 sensor?  I ask for two reasons:

        a. I'd like to be able to unplug it next time it falters and see if the
problem goes away, and

        b. If you can run it without it, what's my motivation for replacing
it?

4. Ron advertises O2 sensors to replace mine that "require splicing".
What's meant by this?  The archives seem full of stories of spliced O2
sensors that don't work.  As someone who's not terribly technically
proficient, I'm hesitant to attempt to solder and shrinkwrap a generic
sensor.

5. Where's the best place to get a stock sensor?  How much should I
expect to pay?  Is it relatively easy to install a stock sensor?  It
doesn't look like it would be a huge problem.

Thanks for the info, people.  Your advice and willingness to share it
make owning a VW a much more pleasant experience.

Steve

Steve Johnson
Anchorage, AK