My '94-1/2 7.3 is all original, and it has developed an intermittent engine shutoff. Typically these events happen at speeds of 40 mph or lower, the engine totally shuts down, no stumbling, just as if switched off. All gauges including volts are normal at these times, but in every case the tach immediately falls to zero. This has happened at least twice with the truck sitting parked, but many more times while under way.

The truck is a 5 speed manual, and so the engine is absolutely turning as the tach reads zero and the truck is rolling to the shoulder to come to a stop. So far it has always restarted - usually after sitting for a minute or two with the key off, a start attempt will be successful. An immediate attempt to restart never works, it has to sit for just a brief time. Sometimes it will run for just a minute or two and then fail again, other times it will run for 20 or 30 miles after a restart without missing a beat. I have zero confidence in the truck, and I'm reluctant to take it very far from home.

Has anyone run across symptoms like this, have some suggestions as to where to start?

 

Sounds like a bad cam sensor (CPS)

 

X2 on cam sensor. Replace only with Ford or International sensor.