After messing around with this thing on and off for the past few months I believe I have finally fixed it tonight.
When wiggling the main wiring harness it would stall & there would be no signal to the fuel pump .
I ended up pulling the ECM , taking apart the connector , jiggling wires ,etc but problem was still there .
After much prodding & poking I cleaned the grounds & tightened the hold down screw which helped cranking but didn't solve the issue.
I pulled the fuse panel out again with the ecm and this time found a slightly loose wire / terminal on the back of the fuse panel . Apparently from vibration over time then also every time I tugged on the main harness it pulled that wire out of the back of the fusebox just enough for the terminal to lose full contact with the fuse . If I shoved the fuse all the way in the fuel pump would prime .
I pulled the terminal all the way out , spread out the pins that hold it tight, snapped it back in snug ,cleaned all the other terminals , put in all new fuses with more dielectric grease .
Unbelievable how aggravating something so simple could be , but at least it didn't cost me anything but time and frustration . All the dielectric grease smeared & mud sticking to it made the problem difficult to see .
Seems to be ok now. I will test it tomorrow.

 

Glad you isolated the problem to the fuse block wiring. It's the simple things that you often overlook.