OK a couple months ago I bought this 1995 6.5 turbo diesel it has 240k miles and it was OK at first now I'm having problems. When starting after the truck has set all night I can crank it and everything is fine I can drive it but it has a little bit of an inconsistent sputter for awhile. But and but will stay running but if I go somewhere go inside and park it for like 30 or more minutes when I go to get back in and crank it it will crank run for about 10 secs and shut off and won't start up until I try cranking it for bout 20 seconds while pumping the gas. Now if the truck is only off for 5-10 minutes it will start fine. I have already put 3 different pmds on it please help me out really struggling

 

Air leak in the fuel lines or filter housing leaking?

 

No not any that I know of

 

The only good way to tell for sure is to replace the IP fuel return line at the frt of the IP with clear diesel rated hose and with the truck safely parked and idling-watch that hose for bubbles.
Bubbles mean air in fuel usually pre lift pump.

A leaking water in fuel sensor or fuel heater can also let air in when the truck sits shut off.