I just had the lift pump changed in the truck and ran fine for awhile but now it won't start just cranks and blows white smoke and sometimes will fire up and only run for a couple seconds? I was told there is some kind of sensor that can go bad and cut off the fuel supply anybody know what that would be

 

The oil pressure switch is what supplies power to the electric lift pump when the engine is running.

AC Delco ONLY for replacement,and google "OPS relay Mod" and install for long term reliability.

The symptoms you describe also show that you have an air leak somewhere between the fuel level in the tank and the IP.

 

The op sensor just doesn't take care of the oil pressure it works the lift pump to.your better off getting one from ss
diesel u can get one from the parts store won't last long

 

Do not deal with SS Diesel unless you like having 0 customer service after the sale,according to what I have read many times-never dealt with Walt myself to confirm because of similar warnings early on..

Your local GM dealer, Rock Auto or get the local parts store to special order AC Delco,or part # D1808A or GM part#12555492.

 

Thanks guys I got an op sensor now just gotta find some time to put it on...what's the procedure on these 6.5's to prime them? It's been sitting awhile but I've never primed one before?

 

The manual says to bleed the fuel filter and just crank for no more than 15 seconds followed by a 1 minute starter cool down period,repeat as needed.

I like to crack an injector fuel line loose to speed things up,tighten once running or after first shutdown.