I have had an occaisional no start problem with my '85 Westy.  On one
particular trip, I noticed it stalled after a long trip, just asI was ready
to shut it down.  I remember tapping the gas pedal, and the tach just
dropped dead and the engine stalled.  After going in to the Park office to
register,  it would not start.    It cranked fine (I have two batteries),
but it would not catch, like no spark.  It eventually started after 30 or
40 minutes or so.   A post earlier today mentioned this problem on their
'85 Vanagon.  The only thing I have not really looked at carefully on this
engine is the distributor (other than new cap, rotor and wires).  I have
heard of others with Hall sender failures.  Would heat cause it to fail,
then work later on?  I thought at the time it was a too lean setting (I had
leaned out the AFM a few notches), the altitude (this was at Shenendoah
National Park, Skyline Drive), or possible the timing being too far
advanced (I am running more advance than the stock 5 ATDC).  The AFM is
back to the original notch and the timing is closer to stock at about 1 or
2 BTDC.   Do the HAll senders just fail or can they just have intermittant
problems, leading to total failure?  I have heard about the connection at
the distributor sometimes failing.  Maybe this is the problem?

                                                                        Jay