Starting problem:
Try tapping the starter with a metal object.
If you don't have a hammer or similar handy, you
can use the front table bracket. First locate the starter
housing. Then when you know the location of the starter,
try to tap it with the long end of the table bracket.
That always got my vanagons and buses going again.
When the problem started to happen on my '90 westy at 80k miles,
I took the starter apart, and changed the grease in the starter
solenoid with a small amount of synthetic high-temp wheel
bearing grease. It seems the grease Bosch uses in the solenoid
is too sticky. I haven't had a starting problem since, and it's
been another 60k miles.
It's a common phenomena with VW buses and vanagons,
and even other vee dubs like Dashers, etc.
I've seen it happen with new rebuilt starters as well.
Good luck.
Harald
'90 westy