I have not had Hall sensor problems with a Vanagon, but I just went thru
it with a '94 Golf.  This one would fail intermittently, which made it
so much more interesting to track down.  On the Golf it doesn't kill the
engine, it just puts it into a default mode which was rich enough to
make it fail emissions testing.  I finally caught it in the act using an
oscilloscope (not convenient on the road).  You may be able to monitor
it with an LED.  In the Golf, the ECU supplies +5 V and the Hall
circuitry in the distributor makes and breaks a connection to ground.  I
don't know if the Vanagon approach is the same.
   I don't even know if an '85 has a Hall sensor.

good luck,
Larry A.

Mark Edwards wrote:
> A friend has a water cooled 85 that cuts out for no obvious reason. Drives
> on the freeway, warmed up, or just starting out, and it cuts out. Pull off
> the road, and it starts back up again. Sit at a light, and it just shuts
> off. Then starts back up. It has never left him stranded, but his wife is
> demanding that he sell the van, as she does not care for the stress
> involved.
>
> I have been through the archives, and its loaded with lots of information,
> ideas, and things to try,  but what I am not going to find in there, at
> least very easily, are reports from folks who have actually solved  this
> kind of issue, and what the resolution is.
>
> In order not to keep refilling the archives with everyone's ideas and
> opinions, for which I am grateful, is it possible to just receive some
> posts from those who have actually "lived through" this with the results
> of what you did to fix the problem? I am guessing there are multiple
> variations on the symptoms, but hearing from folks who have actually fixed
> their vans would be really appreciated.
>
> Thanks for any replies.
>
> Mark
>