sucking air or ?

[dragrdan]

Last week, driving home from work, cruising down the highway ~70mph, my truck died and wouldn't restart. Fuel gauge showed 1/4 tank. The truck is still somewhat new to me, so i thought the gauge was off. Had someone bring me some fuel, put it in, primed and bled the system and it fired right up. Drove it straight to a station and filled it up. Only took 22gals to fill it so guage seems accurate? Ran fine until 2 days ago, again driving down the highway ~70mph it died. Primed and bled it and it started and ran fine. This time the gauge showed a little over half. Today, same thing, died, primed it and bled it out, and made it home. Everytime it died, it started blowin white smoke as it was dying.
Truck is a 93 W250 5sp. Starts right up first crank(except the times it has died on me). Could there be a small enough leak in the suction side of the fuel system that air builds up and gives me problems. I put 350 miles on it between the first and second time it died, and about another 100 between the second and third time. Also thought maybe the lift pump, but oil is not filling, and doesnt smell like fuel(has the diaphragm type).
Spring could be getting weak, but would this cause it to lose prime?
Any tips for checking for leaks in the suction side, there are no wet areas, or leaks that I can see. Truck still has the factory plastic lines, are they still available or will I need to fab something up?
Sorry so long winded, but wanted to give as much info as I can.

Thanks in advance

[gear jammer 91"]

I would say you are getting air in the system somewhere.
As far as the lift pump goes, the injection pump in our trucks is capable of pulling it's own fuel, so if the lift pump fails it should still run ok.
I don't know a good way to find your air leak, other than looking real close for cracks in the lines. Hopefully some one with some experience find air leaks will jump in with some info.

[fergavs]

It may just be the wire on your kill/fuel cut solenoid. Its the brass unit on the IP directly below the boost refernece line coming off the head going to the IP. Make sure the connection is solid and secure. Mine used to make the truck die randomly while driving down the road.

[randyswelding]

wanna diesel told me to get a shop towel and an air hose and then stick it in the filler tube and look that way.hope that helps im doin it this weekend

[dragrdan]

well, think I got it fixed, think it was either the filter at the bottom of the pickup in the fuel tank, or a leak somewhere in the suction side. Intank filter is MIA, replaced by an inline. And upgraded the fuel line to 1/2" to the lift pump. Intank filter looked pretty well gunked up.