I had similar symptoms on my Dodge 3500 with a Cummins 5.9 and found that I had lost prime between the lift pump and the injector pump.
It baffled me because the lift pump was working and the injector pump was fine. It was the air trapped in the top of the injector pump and the tail end of the input line (coming from the lift pump).
When I removed the input line from the injector pump and turned on the ignition it flowed LOTS of fuel. Turn the ignition off, reattach the line and try to start. Nada....
What finally got me going: poured fuel into the top of the injector pump until full, loosely attached the input line to the injector pump. Turned the ignition on and watched fuel squirt all over for 20 seconds then tightened the fuel line. Truck started right up.
The whole process above played out over about 6 hours of tinkering.
Don't know if this helps... If not maybe someone else has thoughts?
If all else fails: Southern Oregon Diesel-Roseburg Oregon 97470
I have had work done by these folks in the past and would not hesitate to call them again. Good (bus) People.
Good luck & safe travels.