Happy Holidays Everyone!!!

I have a 91 D250 Intercooled Turbo Diesel 1st Gen.
Last night, while pulling out of parking lot, when I hit the accelerator, all of a sudden the engine completely stopped running. So I coasted over to the shoulder to where I stopped. Lights and everything electrical still working, just no motor. It didn't slowly stumble to a stop, it just cut out and stopped. Now it won't start at all! After a friend towed me home, I changed the fuel filter, although it didn't have the typical signs of needing a change, and still no start. I checked all fuel lines for tightness at clamps, and the lift pump manual pump lever has pressure, although sometimes it doesn't get pressure when I hit the lever...

What are the most likely possibilities of what could have caused this all of a sudden loss of engine run? Is there an electronic fuel stop in the fuel injector pump that maybe is stuck closed? If so, how would I check this? Would a lift pump issue cause the symptom of an abrupt engine stop run like this? I mean, it didn't slowly die off, it just shut off like a switch!

Please let me pick your brains for your experiences to share. I am totally grateful for any insight you may have. I need my truck for work, and now I am stuck. Please help.

Mahalo.

-Jeff

 

I would bet a hundred dollars that the wire to your fss is loose or off. It is the valve with one wire going to it on the back (drivers side) of the IP. It is G in this pic. Make sure that the little nut on top is tight and that you have 12 volts to the wire with the key on, good luck...Mark

 

Thanks!

There are 2 wires connected there, and they are both connected. I checked, and I do have 12v at the wire G with ignition. Is that the fuel stop? And should I remove it to see if it is working? Please advise how to proceed? Mahalo.

 

Yes, it is the fuel shutoff solenoid. Make sure that the wire is tight, mine was on, but not tight, take it off and squeeze the connector with a pair of needle nose pliers. Some people put an eye type connector on it for a more positive connection. Also make sure that the little nut on top is tight...Mark

 

I check for tightness, and all is tight, including nut. Should I remove the solenoid to see if it works? Or should I check something else 1st?

 

Try running a wire directly from the battery positive to the solenoid and see if it starts. Then go from there...Mark

 

I have 12v with the ignition on, so I have juice. I'm going to try remove the shut off solenoid and remove the plunger so it remains open so I can test. If engine starts, where is the manual shut off lever so I can kill the motor? Thanks!

 

It is just below the throttle shaft in the above pick...Mark

 

What is the "H" part in your picture? could this be part of the problem?

I removed the fuel shut off solenoid, took out the plunger and put back. still no start. What else could it be?

 

Crack an injector to see if you have any fuel, maybe you developed an air leak and lost the prime. Just asking, are you sure that it didn't run out of fuel? There are only a few things that it can be, but this would be good to know, good luck...Mark

 

could it be my lift pump?

 

Yes, but first things first. Do you have fuel at your injectors? Crack a line or 2 at the injector and crank the engine. You should have diesel fuel coming out under high pressure. If not, then you know there is no fuel coming from the IP. The next thing would be to see if you have fuel going to the IP. When you changed your fuel filter, was it full of fuel? Where do you live? If it is cold there, your fuel may have gelled up, but that is something that I know little about, being a desert rat. When you changed the filter, did you fill it up with fuel first? The possibilities include, but are not limited to, a bad IP, a bad lift pump, an air leak somewhere in the supply side causing loss of prime, clogged fuel line anywhere in the supply side, from inside the tank to the IP as well as others that I am forgetting. On the pressure side of the pump, if you have fuel coming from the IP, it could be bad or clogged injectors. The suddenness of the shut down probably doesn't support this, but who knows? Good luck...Mark

 

I was thinking FSS, like Mark, with the sudden shut down...

 

Please explain the process of cracking a line at the injector? Where do I loosen, and do I completely remove injector? Never done this...

Fuel filter was full and fuel looked clean, but changed anyway.
Would a broken lift pump cause the abrupt engine stop that I experienced? I sure hope it isn't the IP...
Where can I check for leaks.
Thank you for your continued help!

 

On top of each injector is a 17mm cap that connects the fuel line from the IP to the injector. Just loosen it a little, you don't have to take it completely off, and fuel should shoot out all over the place. From what I understand, the VE pump can run run without a lift pump, so I doubt that a lift pump failure would cause sudden shut down, but anything is possible. One suggestion, if there is no fuel coming from the pump, is to run a fuel line from a tank of fuel directly to the IP. This eliminates everything from the IP back. If it doesn't start, then we start suspecting the IP itself. First crack an injector line...Mark