I just had the same problems.  If I charged the battery and waited it would start too.
I just installed the hot start relay from bus depot.
Problems are gone.
It's because the voltage and the solenoid is too low due to old wiring.

John.

>>> Kevin Gilbert <kggilbert@MYACTV.NET> 10/25/2005 10:09:03 pm >>>
Dear Volks, oops, uh, Folks,

Sometimes, unpredictably, the starter won't crank. The engine gets up to
normal operating temperature, I'll make a stop, then re-start. There is a
long 1 or 2 -second delay with the key turned, then everything works. It's
never stranded me, but it has worried some faint-hearted passengers.

I have replaced the starter motor, and cleaned the related contacts.

This is an '84 Westfalia with AT, 107K.

Any simple (cheap) fixes?

TIA,

KGG