I have a 1989 ford f250 w?ats turbo with around 230000 miles on it. i purchased it a couple of weeks ago from about 225 miles away and drove it home fine. when i got it home i changed the glowplugs and oil. i then drove it around town (very few miles) a couple of times. The other day i took it out and did some running around, and i ran out of fuel in the rear tank, so i switched to the front tank. It then started surging in 4th and 5th gear and idled rough and eventually died. I suspected there was an air leak somewhere so i purchased a cap, line, and oring kit. Also bypassed the the selector valve straight to the rear tank. Primed the system and it ran great for about 3 minutes and started to over rev about 2 times and died. would start again after cranking for about 30 secs. but die within 30-45 secs.i removed the rear tank sending unit and everthing looked ok in there, and i thought maybe bad fuel, so i fed the lines straight into a fresh container of diesel, But the same thing happened. I flow tested the fuel pump by cranking and got about 1/2 pt in 10secs, though i couldnt psi test it(no gauge) If i keep the motor at about 1200-1500 rpms, it will countinue to run indefinetly with no stall, but as soon as i let it start to idle it will die within about 45sec-1min. Also two last things i have noticed(Maybe they have always been present and the motor still ran fine after discovering them) there is what seems to be fuel leaking from behind the motor somwhere and running down the starter, flywheel cover. I cant see it anywhere and it dosent seem to be from the valley pan or injectors. ALso there is pressure in the upper radiator hose after the motor runs for a while, i dont know if it is from heat and steam, and it seems to g away after a little while of running

 

Upper hose expansion is normal within 2 minutes of running, even when the block heater is plugged in......coolant expands.

There could be a leak from any of the return lines onto the valley pan, it has a drain that will dump oil, water and fuel usually over the back of the engine. So check under the IP for leaks and on the valley pan ...... the drain is the square hole plug (do not remove) behind the intake...... There is one cross over line to the drivers side should be in front of the turbo.... if the PO put it on the rear of the engine it could have a hole burned into it.......or fallen off.

 

all of the return lines and caps were just replaced, and i can not see any of the caps leaking. any other ideas for the leaking fuel? or the stall?