John,

According to your climate, if you are in the cold, (where is FAU.edu?)
the symptom COULD be water in fuel, but I doubt it.

The symptom sounds a lot like the AFM-induced "sputtering on long trips"
scenario I once experienced.  See the Archives at
gerry.vanagon.com/archives/vanagon.html.  The "fix," if it is the
AFM/ECU conflict/peculiarity, is an expensive wiring addition from the
dealer, or, maybe, a $2.19 Tantalum capacitor soldered-in from Radio
Shack, a special order item.  The number is RSU 11295961.  Technical
information re: capacitor is courtesy David Beierl.  The guess is mine,
so caveat emptor.

Tom Hanlon
Palm Springs, CA
84 Westfalia

John Neumeier wrote:
>
> Dear Vanagon Owners,
>
>         Last weekend my 91 Vanagon started sputtering and surging at
> highway speeds after 1.5 hours into a long trip.  When I pulled off the
> road, at idle the motor surged from 500 rpm up to 1500 rpm.  The gas tank
> level was at about 1/2, and I suspected water in the gas.  After filling,
> the problem went away but started again at 3/4 full.  The next day, it
> sputtered a few times when it was cold but no problem afterwards on a 1
> hour drive.  On the return trip, all was well until about 2 hours into the
> trip when it started surging and sputtering again, this time not as bad.
>
>         One year ago I had a similar problem, but it dissappeared after
> filling up.  It seems to me that this could just be some water in the gas.
> Does anyone have other ideas??  Thanks!
>
> John