I vote for Hall Sensor failure. My 88 GL would run along just fine -
then suddenly for a moment - just die....period. hen it would catch and
go again It was a total ignition break - nothing firing. If it were a
fuel problem, I think it would sputter at least a little bit, give some
kind of warning - but mine just quit stone cold dead - then would catch
just as it began to lose speed. This went on a while - then it just died
- won't start. I'm pullling a known good distributor out of my parts car
to try out this weeekend, - but I'm almost certain it's the hall sensor.
Without the hall sensor signal the ECU doesn't know what to do.

John
On 11/14/2013 9:09 PM, Scott Daniel wrote:
> If the tach dips or the needle jiggles say ...
> my thinking would be drawn to the distributor.
>
> I'd try a known good one  for a first step.
> It's mandatory in my world to have at least a known good ECU and
> distributor for self-rescue and testing.
>
> Of the Hall Senders I have seen that have failed one way or another .....
> it's been intermittent no-start cold,
> or ....power loss, stumbling, and fialure to keep running steadily after
> running a while.
>
> I had two distributors in a row do that , 1.9 ones..
> and each one took 3 hours of freeway driving before they acted up.
> ( happened at the same place on I-5 three  hrs north of where I am ..
>   a year apart...exact same thing with two different used distributors,
> same van. )
>
> New Hall Sender fixed it.
>
> It's nice to have another AFM too.
> All I've seen those do is run 'unevenly' after many years. Subtle
> unevenness ...
> I did have one that would allow a 1/2 second cut-out at 60 mph, but that
> was all.
>
> Scott
>
> On 11/14/2013 6:20 PM, Gregory Smith wrote:
>> Heeeeeeeeelp!
>>
>> I am pulling my hair out trying to solve an ignition miss on my '88 GL.
>> When it happens, the engine is warmed up and I'm usually just cruising
>> along.  The engine stutters and the tach dips and even goes up a bit
>> sometimes.  The fuel pump is good, quiet, filter is about 2 months old.
>>
>> Initially I suspected it needed and tune up and have replaced the plugs,
>> cap, rotor, and wires using the appropriate parts from Bosch.  The
>> problem persisted so I replaced the ignition switch with a new one.
>>
>> The problem persisted... reading up on the symptoms I thought it might
>> be "vanagon syndrome" so I swapped in a different AFM, still there.
>> Added the proper capacitor to the AFM innards, still there.  Unplugged
>> the O2 sensor... still there.
>>
>> Any ideas?  Does the hall sender in the distributor do this when it's
>> failing?  I think it's more of an on/off failure so I'm stumped.  Thanks
>> in advance.
>>
>> Gregory Smith
>> '88 Vanagon GL
>> '77 Lancia Scorpion
>> Olympia, WA
>>
>>
>