OK, truck has been spuddering when excelerating, put on psi gauge today and taped to outside of truck to read while driving. gauge went backwards (Vaccum) it would jump a little when starting.. no Fuel psi..

under hood on firewall, took fuel pump fuse and touched it off on hot point and fuel pump works and had psi.. so I guess its telling me that oil/fuel selenoid (OPS SENSOR?) is bad and will have to replace. (again). what about fuel relay? any other ideas out there??

Merry Christmas............

Sounds like your right, OPS is bad... and yes it is very likely bad again.

The only way to fix it is to power the lift pump with a circuit off the fuse panel that's hot with the key on.

OK, update. got the ops changed today. $28.... and YE---HAW got fuel pressure back again.. left the psi gauge on to see what I got.. at Idle 650 rpm---5.5 to 6 psi. and down the freeway at 70 mph running 26 rpm it says 5 psi... thats on a fuel pump with 194k miles....