Last night i was driving my 1991 w250 and it was running just fine, pulled up and talked to some buddies. Left the truck idling for a good 15-20 mins. Went to leave and when i put it in reverse it bogged down and oil pressure dropped, put it back in park and rpm went back up a little. Turned the truck off and checked oil, eletrical plugs, and everything i could think of. Tried to turn truck over and it wouldnt fire, sounded like it wasnt getting fuel but after cracking an injector line it was obvious that it was, would hit like it was tryin to crank but never would. Drained water out of fuel filter and still nothing. Assuming that maybe a plug im not aware of may have rattled loose and i havent found it but before tearing anything apart i figured id see if anyone else had any ideas. -Thanks

 

Any obvious leak on the ground, diesel or oil?

 

No, i found i plug unplugged behind the fuel filter. But now i have a problem with it turning over, yesterday it would turn over and not fire, i would try different things and try turning it over, then all the sudden it quit tryin to turn over and i got a whinning noise coming from down by the starter and lift pump. Replaced the starter and its still doin the same thing. it only happens right when u turn the key on and quits after about 5 seconds and at the end theres a sort of thud.

 

The humming and thud is the grid heaters cycling.

Is the wire still on your FSS? There is one on the side of the pump (KSB) and one on the rear(FSS).

Try jumpstarting it or charging the battery?

The plug you found was the fuel heater.

Post this in the 1st-gen section.