hi im new to the site and pretty new to 12v engines i recently bought a 98 12 valve. pretty solid truck with a little issue im working on, the truck starts hard like it looses prime then finally starts and idles fine for 5-10 min then gradually starts idling rougher up to the point of almost dieing. any ideas where to start?

 

Most likely the fuel delivery system is sucking air somewhere.
It can suck air but not leak fuel.
Easiest way to find leaks is to pressurize the tank though the fill hole with 5 psi max pressure compressed air.
Most common leak spots are the fuel heater and the hose in red below.

 

thanks for the info ill see what i can find out