I had the same problems with my 85 Westy.  Exactly the same problem.

I took it to my all-knowing VW specialist.  He said that there are two
things that could cause this.  First was the O2 sensor.  He disconnected
it.  All was good for a couple days and then instead of bucking, it died
going up hills on trips, especially while it was raining.  Of course it
was a very thirsty little van as well.

Then he disconnected the throttle switch.  The van ran like a
bat-outta-hell afterwards.

I could be wrong about the order of things he disconnected.  But I know
that he did not replace anything, because he didn't charge me.  Instead
of disconnecting something, he may have bypassed one of those two
things.

This guy is the reason I own 2 VWs.  Tracy, pmail me if you want more
info.

Dana
'85 Westy with no friggin name
dshowers@cpds.net

Ok, so I couldn't figure out what the problem was. I am having a irradic
idle, that slowly goes down until it stalls, loss of power ( especially
uphill ) , and surging / bucking. I was told to check out some grounds,
and the ECU, and some other things. I checked them out and still
couldn't figure out what the problem was. Then today I noticed that I
was going through gas like crazy. I stopped at my mechanics, and he took
one swipe in the tailpipe and noticed that I was burning alot of gas,
and it is running rich. He said that I have a fuel system problem, and I
have an appointment for next Thurs. My issue is that I'm low on fund$
and so I was hoping that someone on the list might have an idea of what
it could be. Buying parts and doing it myself would be alot cheaper, not
to mention it would get done quicker than next Thurs. Please let me
know.

thanx in advance,

Tracy

85' GL "Ripple"