Truck Repair: 97 12V 5.9L Stall after start issue, performance issue, check valve

Question
My son has the 97' 5.9L Diesel and it is having basic performance issue's. 1) if the truck is parked overnight on a hill (with the front end higher than the rear end)the truck will start and run for not quite a minute at idle. Then it stalls. It takes several attempts to get it to start and run.
2) at high rpm, he is having indications 'missing'.
I told him I suspected the fuel solenoid on the injection pump was leaking fuel back to the tank, allowing the engine to idle on the fuel in the filter. When the filter fuel is used up, the motor stalls. What is the recommended fix for this problem.
As for the 'missing' I suggested that the injectors are probably damaged from water or air in the fuel causing a poor injection pattern. Does it make since to pull the injectors out and have them checked? Do you know what the standard injectors are for the Stock 97' 5.9L Cummins?

Answer
It is not the fuel shutdown solenoid causing the leaking back overnight.It is either the transfer pump or the return check valve on the inside on the fuel pump(fitting where the fuel return line hooks next to head).I dont know what the injectors are flow wise but the data tag sometimes has the injector part# on it.Usually if an injector was bad it misses all the time.