I had the same surge/buck with my 83 WB.  I cured it, with the following:

1.  opened AFM and repainted carbon trace on circuit board with conductive
carbon graphite paint, found at
http://www.2spi.com/catalog/spec_prep/cond_paints3.html#7

2.  soldered an electrolytic capacitor between AFM wiper arm and ground.

It's been buck free for over 2 years.  I'm not which fix was needed, but the
repair cost less than $10 in parts.

Duane O'Donnell
Oroville, CA

>Date:    Mon, 17 Dec 2001 10:32:54 -0800
>From:    van man <vannman99@YAHOO.COM>
>Subject: Buck/Surge symptom at highway speeds??

Howdy,

Saturday morning while driving on the freeway I
noticed a sudden bucking in the 87 syncro.  The buck
happened a couple of more times while on the freeway,
then ceased until I got to my destination.  While
comming home that night, it started again (at freeway
speeds) and happened three times within about 5 miles.

This morning on the way to work.. bam- there it was
again at freeway speeds (65-70).  I slowed down to 60
for the next 30 miles and it didnt buck again.

The buck is kind of hard to explain.  At first I
thought it was more like a power surge - but how much
power surge can I be getting at 70mph?  It almost
feels like Im hitting a bump... The rear of the van
seems to almost lift a bit, I think I can hear a clunk
like sound that seems to be from the rear.  I havent
down anything back there since doing the CV's about
5000 miles ago.  Only other things Ive done recently
is rewire the tachometer and replace the battery -
both the night before the symptoms started.  I know my
throttle switch is bad - one of the screws is broken
and I idle high and sometimes have a buck in first
when I let up on the gas - but this new buck is always
at 65+ with the pedal not to the floor, nor am I
letting up on the pedal when it happens.  Its pretty
significant and a bit frightening..

Any clues?

Thanks

jeff

_________________________________________________________________
Send and receive Hotmail on your mobile device: http://mobile.msn.com