Originally Posted by Sniper
I am sure the FSM mentions an expected pressure and maybe even a +/-. In any case, a 15 psi fluctuation is not good.

I followed the FSM and the static pressure is within specs, as is the leakdown and fuel flow test.

At about 35 mph, the truck will start bucking and try to lay down. backing slightly off the throttle will calm is some.
Is this a plugged fuel filter symptom?