[cintocrunch]

Air, fuel and fire. If you are pretty sure it's not the fuel check the fire. More than once people have spent a lot of time chasing down fueling issues that were spark related. Start at the plugs and work forward.

Are you getting any misfire codes? Does it feel like it's down a cylinder? Could try swapping wires or plugs to rule them out. Start at the plugs and work back.

 

[cintocrunch]

Have you poked around the wiring for the fuel pump with a meter? I'd be interested to know while you are getting 0 PSI what voltage you are seeing at the relay, fuse, connector at the pump, etc. I know you said the pump is difficult to get to but it sounds like it could be a loose connection or if you are having another sensor that is cutting power to the pump you should be able to trace back to that through the wiring.