Do you have any smoke while cranking? The multi in these trucks does not care much about fuel quality, only quantity. When I picked mine up, the JP8 or Diesel was likely 10 years old or so. It smelled like varnish more than it smelled like Diesel. The truck ran strong on that mixture but did emit quite a bit of white smoke and finally stopped 120 miles later due to water soaked filters. We fixed that, refilled the tank and were good to go again. This question has been answered more times than a few, pull the cover off the side of the Injection Pump and ensure that the fuel shutoff is moving. The cover has 2 flathead screws that will be safety wired together if it's never been removed. Have a friend pull the fuel shut off out and push it back in. Observe the movement of the bellcrank attached to the fuel shut off. It should move smoothly. It's not connected directly to the shut off cable when pushing in, only when pulling out to stop the motor. When pushing in to start, it pushes against a spring. If the bell crank is binding as the fuel cable is being pushed in, you have some work on your hands with some PB Blaster. Inspect as I talked about and post back. We'll help get it back on the road.