I just had the same problem after putting in a new distributor.  The engine
would cut off and the tach went to zero immediately.  When I toggled the key
while rolling without engaging the starter, it "started" back up.  I changed
the ignition switch and have not had the problem again.

Thanks to the group for helping with the ignition diagnostic.

It is my understanding that the HAll sender gets replaced when you put in a
new starter.

Rob
90'Westy

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
Of Allan Bagley
Sent: Tuesday, January 29, 2002 11:04 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: '85 (Digijet) Hall Sensor Symptoms

Is it overly simplistic to assume that if the engine looses power
momentarily at hiway speeds and the tach zeros at the same time, even though
the engine is being spun by the transmission, that the Hall Sender has
failed or at least ceased sending for that moment? I tend to think that the
tach zeroing at the moment of the 'stumble' or 'hesitation' is a giant clue
and would tend to rule out AFM and other items in the fuel chain. I can only
assume that this could be caused by a faulty Hall Sender, ignition switch,
wiring to the distributer, or what else?

Allan Bagley
86 Westy

-

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
Of Mark Ingalls
Sent: Monday, January 28, 2002 7:06 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: '85 (Digijet) Hall Sensor Symptoms

>>>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 >>>>

If the hall sender is working, you will see your tach 'pulse' while the
starter is cranking.

Mark Ingalls
85 GL