Truck Repair: Mechnical 8.3C cuts off, rhime, highway speed

Question
Cliff, I have an 8.3C cummins in a 1993 RV. Without any "rhime or reason" the engine will just cut off. This may do it sitting still at idle or moving at highway speed. Can happen when cold or after hours of running. Rough roads do not have any effect on it cutting off. The last time this happened, it happened 6 times in 12 miles. As I was several hundred miles from home I wired the fuel shutoff solenoid up and had no farther problems. I have checked and cleaned the 3 pin connector at the solenoid, wiggled the wiring near sol and ignition switch and can not make it shut off. I suspect the hold in part on the solenoid is not doing it job but thought I would ask your opinon before spending $330.00 on a new one. Is it common for this part of the solenoid to fail?
Thank you for your help,
Jim

Answer
Sorry,my internet crashed yesturday when I tried to answer your question.
Yes they do go bad especially if it is the original one or the small style.The solenoid kit has new brackets,solenoid,& bolts to install the new larger one.I thought they were $250 for the kit.I know they make one for Ford & one for everything else in the vertical position.