Hello all! while I have been waiting to get set up on the board here, I have been working through my trucks problem and reading the relavant posts I thought might help with the issue my truck is having.
First off the truck: 1993 W250 pretty much bone stock. it has the 4500 lb axles and an NP203 transfer case.Oh and of course a Cummins. Pretty basic but a good dammn truck.
A few days ago it just shut off on me --right outside the garage door as luck would have it and would not restart. At first I thought it might be the fuel shutoff sel problem but I was able to rule that out that pretty quick. The selonoid is in great shape including the plunger and electriclly its fine. Checked the lift pump( less than one yr old) and the filter and worked up to the injection pump and eventually out to the injectors. Now what happend was I cracked open the injector lines at the injectors and cranked the engine till I got fuel spraying out --Ok, then tightened the injector lines and bingo! she started after a crank or two -- ran fine and died two mins later. I repeated the process a few times and each time she fired up but each time she died the lift pump had lost prime. At first I thought maybe I am actually out of fuel ? so I added 15 gallons and repeated the process she ran agian and died sure enough the fuel system had lost prime agian ***????
could there be something in the tank blocking the intake or is there something else I am overlooking? could there be a blockage in the line? I was thinking I should put some air on the fuel line from the tank and see if I can blow it clear or would that hurt something in the tank?
I am thinking I am going to have to drop the tank one way or another (figures I come to that AFTER I add 15 gals) is there an easy way besides siphoning to drain the tank ??

 

i've seen this happen in gassers and our 6.5 chevy diesel. The pickup in the tank has a little filter on it. If it's dirty in your tank, that filter will pick up dirt until it clogs and the engine dies. You should clean your tank and fuel system, and replace all the filters if your haven't already. i hear the easiest way of dropping the tank was to unbolt the bed and slide it off. Also, try gutting your shut off solenoid and see if that works, and make sure all the electrical connections on the pump are clean and solid.

 

I'll bet it's sucking air somewhere.

 

I agree probably sucking air. check lines for leaks

 

When mine was sucking air it would start hard but run fine once it did fire.

 

Here is a simple test that you can do to see if the fuel lines in fact do have an air leak :


Dis-connect the fuel draw-line at the in-feed of the lift-pump, 5/16" I think.

Dis-connect the draw-line at the top of the tank.

Temporarily connect a LONG length of fuel hose at both points.



Or, even simpler, you could stick the tank end of the hose in a jug of fuel; a big jug or the return-line will soon suck the jug dry.

Work the hand-pump on the lift-pump until the lines are purged of air.

Fire it up and see if it remains running; if so, then either the metal hard-line, or either of the short rubber sections, has a hole somewhere.

 

My 93 has plastic fuel lines and my 89 has metal.

 

Doesn't it have a 205 t case the 203 is full time chain drive ?

 

Your correct it has the 205 not the 203. My old 86 W150 had the 203 chain case in it.
Got the tank out today the rear strap is fubar....... gotta find anew one of those. The supply and return lines in the frame rail next to the tank were swiss cheesed with rust especially at the frame clamps. I was surprised to find it had the 94up style in-tank module. So what I am going to do is get some nylon fuel lines with the appropriate quick disconnects--there is a supplier here in western PA that has all this stuff on hand-- on the tank end and re-run the lines to the lift pump and return line at the rear of the engine.
I think the hardest part will be finding the right tank strap. From the looks of it it wouldnt be too hard to fabricate something if need be.
since it had the quick disconeccts I got it down full --now I can get the fuel out over the next few days during the parts scrounging . I dont even want to think about getting it back in there full !