Have you tried tapping on your ECU? I just went through this with a
friend's Syncro. His van would do the same, just die, then he could
easily re-start it. It turned out to be the ECU. I admit, this is
rare, but it happened. A simple check. Just have it idling while you
gently tap on ECU. Also, have you checked your Hall Sender? These tiny
wires sometimes short out, interrupting the RPM signal to the ECU.
How about your ignition switch? Have you idled it and jiggled the keys?
Miguel

I have not failed. I've just found 10,000 ways that won't work.
  - Thomas A. Edison

On Thu, Mar 18, 2010 at 8:11 AM, Trooz <trooz@roadrunner.com> wrote:
> I finally got the big problem fixed; now I have a mildly annoying one.  My
> van will suddenly die at idle occasionally.  It starts back up with no
> problem.  There are no obvious preliminaries indicating that it's getting
> ready to quit, no coughing, no sputtering, it just stops.
>
> I just replaced the spark plugs and the distributor and the temp II sender.
> Other than those items it's basically original with 218,000 miles.
>
> Anyone have an idea as to what might be wrong?
>
> Bob Trousdale
> '90 Westy
>