Uneeded replacement on my part.
The truck started later, so I was unable to determine what the culprit was. Having replaced the fuel pump and filter last year with simalar symptoms, I called Phil and ordered a new pump. Replaced it and the wife drove the M-class a couple of days, maybe it was one. It died again after leaving church while I was hefting trusses up on my new garage.
Bringing a load of tools to the gas station 20+ miles from home, I tried, but my wife ran the battery down as she'd been sitting in the hot sun for over an hour. I turned blower motor and the key off and set about looking around. I pulled the brass cap off the fuel rail. I did have some fuel, but no sure how much is expected in a hot soak engine. It kind of bubbled out. I brought a timing light, so I put that on and asked my wife to crank the engine. I didn't see any flashes immediatley but then saw some and the truck started up. Hmmm. That's great. Another intermittent.
A couple minutes later the truck stalled. I put the light back on. No flashes, therefore no spark. This must be a CPS problem. The ECU must need CPS to determine crank. If it doesn't see the crank, it won't turn on the fuel pump nor will it trigger spark.
Looks like another parts order.
