S!, I've got a 2000 F450 7.3 4X4 ambulance (running Mobile treatment oil patch) its been a real pain trying to figure her out. I have to open the fuel drain on the filter and close quickly, then unscrew filter cap just enough to see fuel seep, then crank engine over and she starts!! If i don't go through this prcedure she won't fire! When I do get her running she runs great!! Had her to the Dealer for a diagnosis, they want to replace engine " no or little compression" (typical of the dealers)!? There is no smoke and she will out pull (grades) the 2005 F250 6.0!? There is plenty of power, Fuel pressure reads right. I can normally get her started after a "short" shut down but if its a prolonged shutdown I have to go through the "procedure" again! Its like the fuel is sucked back and I have to "bleed" the system at the filter to get her to start/run. Any help would be appreciated.

 

just a shot in the dark, are the o-rings on the fuel drain valve leaking letting the fuel filter housing go empty?

 

Take out the fuel bowl and go thrue it. check orings, hoses, clamps, and the filter housing itself. And the lid to see if there are any cracks.

Nathan

 

There's a mechanical bellow-type lift pump in the valley under the fuel filter housing....chances are that's your problem.

Also check the return lines going back to the tanks for blocks and/or pinches.