You really can't check a ground very well with an led test light. It doesn't take very much for them to illuminate. Could have a cracked flex plate but that does require removing the trans to verify. Are you sure you didn't pinch the crank sensor harness? That was pretty common back in the day.

 

Good point on the need for current to test the grounds, Tizzi. I should have mentioned that I have been using my home-made test light that uses a brake light bulb hooked with each isolated wire in series with the car battery. While the heavy bulb was lit, I pulled on the wire, connectors, and wiggled stuff around in an attempt to determine whether maybe I had broken or corroded internal strands or bad connectors. So far, I have used the heavy bulb to test the wiring from the PCM to: the ASD relay, coil pack, TPS, CkPS, CMPS, CTS, and related grounds. I have found none that so much as flickered. But I have not tested every wire. Today I started a more methodical heavy current test of every wire in the PCM connector, but the incessant rain stopped me cold, or I should say - wet.

I have been using the LED test light as a poor man's scan tool, in an attempt to "catch it in the act." The LED light I spliced into each wire as close as I could get to the PCM connector socket where I had run the heavy test light. The other LED wire was clipped to the + battery post for testing the ground wires, and to the - post for testing B+ wires. The idea was to watch the LED when the engine cut out to see if it flickered with the "miss." The LED remained steadily lit on all of the PCM grounds tested when the engine was missing. The LED flickers with the miss when spliced into the wire connected to PCM pin 57 (DG/OR inj sense) that feeds 12V from the ASD to the coils and injectors. The LED also flickers when spliced into the wire from the PCM that controls the ASD relay - (PCM pin 51 DB/YL automatic shut down signal). So far, I have driven about 150 miles on my little test loop checking wires one at a time in this way.

A malformed socket on the PCM connector, pin 51 would cause this problem. The connectors all look to be in pristine condition, and I have been careful not to enlarge the sockets while testing. Nevertheless, I will have a real close look tomorrow at socket 51.

RE crimping/pinching: I have not had any difficulty with the connector or wiring to the CkPS. It all tests good to carry current. And the new sensor acts just like the old one.

 

While checking out the socket on the PCM connector, (looked okay) and trying to figure out how to remove one of the sockets from the connector to make absolutely sure the socket was tight on the pin, I noticed the part number on the PCM - 04797932. Just to see what was available, I checked out car-part.com in my area for a junkyard PCM. The part numbers came up different for a 94 T&C van - 04686785. Did some checking and found the PCM that is currently in the van is spec'd for a 94 AS body van with a 3.3 engine. So, I figure what is in the van now was not original equipment, and for all I know, may never have worked right. Maybe the PCM for the 3.3 would work okay with a 3.8 - maybe not. Anyway, I went back to the wrench ' go this morning in my high rubber boots and got the right PCM - don't know if it's any good, but at least it is the right number. While I was there, I pulled the perimeter harness so that if i had any connector troubles, I would have some spare parts. Got a radio, too, but don't know if it will work. It is a simple am/fm with no tape - the van has the Infinity sound system option. Now I need to re-install the new CKPS and plug in the new PCM and see what happens.

 

Installed the correct ($32 junkyard) PCM and re-installed the new $32 crank sensor and (dare I say it - fingers crossed) it seems to be fixed. Woo-hoo! Judy and I took it out for a ride tonight around the 10-mile loop that gives a chance for a sustained acceleration to highway speed up the ramp on to the interstate, and it did not miss. Set the cruise at 68 and it stayed within 1 mph without dropping out. Drove around town a bit, bought a cone and made the loop again - still no miss. It has never gone that long without cutting out, so we are hoping it is now fixed. I don't know if it was the wrong PCM or if the PCM for the 3.3 engine was faulty, but either way, I am now a happy camper. I am looking forward to starting more fun restoration stuff on the van.

A big thank you to Tizzi1 and Master Tech for taking time to wade through this complicated diagnosis and for offering encouragement and advice. It is really helpful to know that there are guys out there who are willing to take the time to help a stranger in need.

I will try to take some pix as I re-assemble the dash to pinpoint the ground locations so it won't be so hard for the next guy.