Sounds like you might have a bad ground somewhere that is causing the
available voltage for the ignition controller or computer to drop during
cranking.   I would check the voltage at the computer, at the ignition
module and at the alternator terminal - - - between those terminals and the
body ground connection points that the respective modules connect to  - - -
while you are cranking the engine (pull out and ground the wire from the
coil to crank safely.)

Dave

At 06:36 AM 6/18/98 -0700, nyquist@ACSU.BUFFALO.EDU wrote:
>I recently posted this question about difficult starting of my 91 Vanagon.
>One out of 10-15 times the engine would crank about twice as long as normal
>before starting.  My mechanic had found that the voltage in the Hall
>sending unit was dropping to about .2 volts when this happened but couldn't
>figure out why.
>
>Well......, we replaced the Hall sending unit (new) and now the difficult
>start  is almost a constant problem.  It either cranks and starts when you
>turn the key or you have to crank it once, stop, then do it again - maybe 3
>or 4 times before the engine will start.  This isn't doing my new starter
>any good I'm sure!  Ignition switch is new too.
>
>So?  Could the new Hall sending unit be faulty?  Would it be the
>distributor?  Possibly a computer problem?  Can any of these be tested
>without replacing  them?  Should I go to the VW dealer
>(Aaaaaaarrghhhhhhhhhhhh)?
>
>Also:  There is one fuse that serves the rear wiper and the rear auxillary
>heater.  My rear wiper motor hasn't worked in a while but I keep blowing
>this fuse so then the rear heater doesn't come on either.  I replace the
>fuse and the heater works it seems until the next time I drive the van and
>try it.  Then the fuse is blown again.
>
>THANKS for any advice.  I want to get these things fixed and working before
>I sell it ( I posted it for sale earlier this week).
>
>John Nyquist
>nyquist@acsu.buffalo.edu
>