I thought I had my problem solved after cleaning all my grounds and
repairing some broken wires. I also replaced plugs cap and rotor. It
was sporadic prior to the steps above then it cleared up. Now it's
continuous.

As soon as the temperature gauge starts to register the van starts to
run rough, quickly looses power, then dies. I found that if I switch
the key off, then right back on it will run fine for about 30 seconds
then it starts over. As soon as I feel it running rough again, I turn
the key off/on quickly and get another 30 seconds.

It doesn't matter if I'm driving along or idling at a stop.

Since I got the van I've noticed that it takes a good 10-15 minutes
(or longer) to warm up. When warmed up, it's barely outside the "white
zone" on the gauge. I had planned to replace the thermostat, but can't
imagine this is the cause of the problem.

It sounds like ECU is getting bad info from a sensor. Does this sound
likely, and if so, what should I consider first.

I did try searching the database but it timed out.

Thanks for any suggestions as to where to start.

-Mark K