Dodge Diesel/Cummins Mechanic Advice Needed

Check your fuel line connections. Not sure if they are the same on yours as they are on mine (I have a 98 with a 12 valve), but I had similar issues and the plastic connectors that connected the fuel line on the motor at the lift pump to the hard line on the truck frame got brittle and was letting air and junk into the line which was clogging my fuel filter and causing the lift pump to lose its prime when sitting.