Install a cheap-o type fuel pressure gauge at you filter. If possible mount the gauge where you can see it from the cab ( not in the cab).
If you loose pressure, then look at the pump or tank. A normal pump should be in the 3 to 6 psi range, bur even 1-2 psi is enough to run a engine.
If you have pressure but engine still won't run, look at the carb needle and seat, or carb inlet filter.
With the gauge mounted between the tank and pump, a high vacuum on the gauge and engine not running could one of the following,
(A) the tank pickup is clogged
(B) the rubber or steel line is bad
(C) the tank vent has a problem
A good test is to use a clean fuel jug mounted in the bed running to the pump with new clean fuel line. This eliminates fuel tanks and lines. Dirt in a tank can be tricky, it gets sucked up and plugs off the flow till the engine quits, then the dirt settles back to the bottom till the cycle starts again. It only takes a second for the dirt to fall off the pickup up tube and free up the flow.
Joe
