Fuel pump ?
The easiest things first, on passenger side of transmission hump, pull back the carpet and check the inertia switch has good connection. After that I would try the fuel pump relay in the power distribution box under the hood. I would say 80% chance it will be one of those. BUT if not the pigtail off the fuel pump has a connection in the frame rail right in the vicinty of the rear driver side shock.
The fuel pump relay is about $15.00 new I think. I use a relay right next to it to switch with and verify before you go buy an electrical part you cant return. Or else if nothing else go to wreckin yard and pocket part them babies. Or not and give a few bucks for em. If these symptoms just started and maybe wet moist weather seems to effect the starting then if not these 2 points to check, then maybe moisture getting into wire harness somewhere.
I recently dropped my tank changed the fuel pump, put it all back together and still NO Fuel pump,, I was FLAMIN PO'd.. It was about 5-6 hours to get this all done away from home and I only had a barn to work in. My cousin stepped in and slammed his feet hard on the floor and disconnected the inertia switch. I wanted to hit him (again). Yep,, And HE
had the black eye and busted lip from when I DID have to hit him.
Anyway Hope this helps. Good Luck