John,

Your first problem may be the well known, but perhaps poorly understood 
problem that many water cooled Vanagons have.  The way to know for sure is 
to stop when the problem starts to occur, turn off the engine, immediately 
re-start the engine and continue driving.  If the problem has cleared up, 
you have the well known problem.

I just told you what the work around is.  There is a wiring harness fix 
available from VW for $200(?).  Also, other folks have found a fix by 
adding a few parts to the computer or wiring harness.  Perhaps someone else 
on this list can point you to server that holds the extensive discussion on 
this subject.

I use the work around.

Mike