Hello, I have a 7.3L IDI, I have had the truck around a month. One day a few weeks ago it randomly shut off cruising down the road at 70 mph. It would restart without hesitation, but if you tried getting above 2000 RPM it would cut out completely. I have changed the lift pump and checked for water in the fuel. The FSS shuts the truck off when the connector is pulled, so i figure it is working correctly. and the high idle air solenoid seems to be working correctly as well. I took the truck out after the lift pump was replaced and i got 20 mi away from home and it did it again. I was able to get the truck home but had to keep it at lower rpm's. The truck runs excellent and starts great but i can't figure out what is causing it to do this. PLEASE HELP, im a diesel technician in training but am not very familar with these IDI's

 

next time it shuts off like that, pull the fuel filter off and see how full it is. if it isnt full, u have a supply issue.

 

ok thanks i havent pulled the filter off but it has plenty of pressure when i press the relief at the top