John, I was having a similar problem with my 90 Carat.  I thought at
first it was the coil so I replaced that.  Still would sound like it was
starting on three cylinders and then smooth out.  However the problem
kept getting worse.  It would stall sometimes and then it started to
stall after the van got warm while driving at 50 mph!  I put in my
digitool ECU and couldn't really see any problems.  The stalling
continued and I knew that since I replaced the coil and the ECU was also
swapped that the only thing left was the hall sensor in the distributor
or a wiring issue.  Sure enough I swapped in a known good distributor
and that fixed the problem.  Now it cranks right up, idles smooth and no
more stalling.  I bought a new hall sensor (from my favorite parts
vendor Van-Again :-) and installed that last night.  Runs even better
than the known good used unit.

I have always thought that the hall sensors fail completely but I guess
this is not true.  I had been struggling with the van running rough and
dying in extremely cold weather as well.  I guess I will have to wait
until this winter to see if this fixes this problem as well but I think
it will.  If your van is taking a while to crank up or seems to be
starting rough then I would suggest taking a look at the hall sensor.
We have these available as a unit alone and then you have to rebuild
your own distributor (not that hard) or we have rebuilt distributors
from Bosch (look like brand new) with a new hall unit inside.

Let me know if I can help you further,
Ken Wilford
John 3:16
www.vanagain.com

John Runberg wrote:
> Installed a newly rebuilt AFM this evening and OH MY does the van
> drive better. Org unit was not very drivable (no power,
> hesitation...) and the "known good" temp unit hesitated just off
> idle. Now, it's SOOOOO much better - best $350 I've spent in awhile.
>
> But (and there's always a but) she still seems to run rough when
> first started, warm or cold outside. Rev a few times and it settles
> down into a normal lope (not perfect, but much better). To recap,
> we've done cap/wires/plugs/rotor, found and fixed a nicked ground
> wire to the dizzy, found and fixed two loose vacuum connections and
> all grounds look shiny and good.
>
> Next plan is to test the vacuum pressure and check the timing. Also
> need to lube the dizzy (exactly what am I lubing in there?). Ideas?
>
> john
>