I've recently installed a FASS 150 HPFP with big line kit, Jammer III's, Juice w/ Attitude and now my fuel pressure will go from 21 at idle down to 0 when I'm into the fun pedal. My diesel tech tells me it's probably the draw tube and screen that's clogged. I'me getting the tank cleaned with a new straw & such put in. I was curious as to how many of y'all have had the same problem. It's not the relay and the filter is new, so we know it's not that. Also the wiring harness that connects the two computers has been replaced which I am told can also interfere with lift pump function.

 

It takes some really dirty fuel to clog the tank screen. The screen is designed so that fuel sloshing around in the tank cleans it. My bet is after removal you'll find a clean screen.