Truck is an 89 model. Sometimes, usually on the highway, the engine will suddenly without warning cut out. If I turn the key off, then on it will come back to life. I am suspect of the fuel solenoid or power being taken away from the solenoid. This truck has always been an electrical nightmare. Any ideas?

 

This thing was full of dirt and oil evrywhere when I got it from the contractor. Cleaned every electrical connection I could find and used die-elctric compound. No problems since.

 

Check the spade terminals at the fuel shutoff solenoid. Over time, the plastic covering can become brittle and the spades lose there contact. Mine would die going down the road about a year ago. I replaced the spads with ring terminal. No problems since.