Have a 90 F250 wit 7.3 IDI. Had it for about 7 months, Did lots of basic drive train work and body work but engine was running so I left it alone. Was told the rear tank leaked when I got it so I never usedd it. Eventually dropped the rear tank and replaced it, usedit for a bit but got into a habit of relying on the front tank. Decided to try the reartank yesterday, engine was warm, just put fuel in both tanks, hit the switch and engine started to die, flipped back to the front tank and engine died. Was close to home so I pulled it home with my Dad's truck. Blead every thing as your supposed to. Switch still set on fron tank. Engine fires rite up, runs strong for a few seconds then dies, it will do this repeatedly. Blead all the injectos several times. Can't figure this one out. Any help?