Do you have power to the shutdown solenoid? does it faintly click when the ignition is turned on ? If that little solenoid is inoperative for any reason then you have no hope of getting fuel at the High pressure lines.
I doubt that the manual shutoff would be causing the problem because it has a spring that returns it to the run position automatically. If the spring is missing , try the start with the lever fully forward and if no go , try it fully aft.
Turn off the raw water
intake to avoid filling the exhaust
if you are doing a lot of dead cranking.