It sounds like the throttle position switch is just barely out of
adjustment.  I have had this problem before and couldn't figure it out
until I had my digitool hooked up and I could see that the switch was
working when the van was cold, but when it heated up it would stop
working.  Check and adjust the switch per Bentley and this should fix
the problem.

Ken Wilford
John 3:16
www.vanagain.com

Barrett Willet wrote:

> '88 2.1l Vanagon Wolfsburg
>
> Recently started having troubles with hesitation during acceleration in
> the afternoon when heading home from work.  Makes you think twice about
> when to pull out into traffic.
> Routine works out like this...
> No problems with idle stability and no hesitation in the morning on the
> way to work.
> After the van has sat for the day and I start out for the trip home the
> idle is acting pretty erratic(500-900) and the van hesitates when
> accelerating from a stop.  Almost feels like its starved for fuel.
> This hesitation goes away after a few miles or so but the idle remains
> erratic and I experience a slight bucking but pretty rarely.  Not the
> vanagon syndrome type of bucking
> All of these symptoms happen in the afternoon and are gone in the
> morning.
>
> Replaced the following due to other issues and preventive maintenance
> less than a year ago
> O2 sensor
> Temp II sensor
> spark plugs
> rotor
> dist cap
> plug wires
> fuel filter
>
> Idle Stabilizer Valve is humming but of course I can't tell what its
> doing while I'm driving
> Ran 4 oz of Marvel Mystery Oil in the gas for 2 tank fulls
> Plan to check continuity of plug wires and condition of plugs on
> Saturday.
> Replaced and soldered new ground connector for Hall Sender.
> Inspected Hall sender and no signs of connector cracking or broken wires
>
> Would appreciate any advice on where else to look.  Searching the
> archives resulted in too many dead ends or discussions about vanagon
> syndrome
>
> Thanks
> Barrett Willet
>