ok, I cracked open the injector lines 2 at a time. There were only 2 that had fuel coming out, the rest were wet with fuel, but no flow. The 2 that had fuel coming out, flowed out when turning the starter, but not gushing out. Yes, I have fuel in the tank, and remember I also removed the plunger from the FSS to eliminate it as part of the problem. Any thoughts?

 

Try priming your lift pump and see if it gets hard to pump, I stopped my truck at a drive through and it would not restart, the diaphragm broke loose off the pump shaft, a new pump cured the problem, replaced in right in the parking lot.
Also your FSS should produce a faint click when it is energized.
BTW is your truck a 1991.5?
Jim

 

Is the connector, labeled H in your picture, the power to the injector pump? if so, i don't have any power going to it. Where is this power coming from? If from a relay, where is it and what does it look like? Thanks a bunch. I'm hoping I can fix power to the pump to get it going...

 

sometimes the prime lever has pressure, sometimes not so much. But never hard to pump. Is this normal?

 

Bump the starter, the lever rides on the cam and could be on a high spot.
Also the reason I ask, 1991 and 1991.5 are set up diffrently with 1991.5 having a relay.
Is yours factory intercooled?
If it is you have a relay on the fender.
You can swap it out to see if it starts.

 

H is the KSB and just advances the timing a little. It sounds like you lost your prime, either a broken/bad lift pump or a fairly large air leak. Did you by chance try to tighten the fuel line to the lift pump when you changed the filter? That is what I did and I split the threads and caused a massive air leak. I am not sure, but when they "gut" the fss they take out the shaft and the rubber. I have never done that so I may be wrong and maybe somebody will chime in...Mark

 

I did tighten all fuel line clamps including to the lift pump. And I did gut the fss taking out the shaft and the rubber.

Where does the injection pump get it's power? I don't hear any noise coming from the injection pump when I turn on ignition. And when I cracked the injector lines I only got fuel to come out of 2 and 5. And it slowly flowed out, not high pressure mess. You think maybe no power to injection pump? How can I test it and its relay? Thanks.

 

It is intercooled. What does the relay look like, and how do I test it? I don't believe there are wires connected to the lift pump though.

 

The VE pump is completely mechanical, it gets its power from the gears on the front of the engine. The FSS and KSB are ancillary to the pump, the FSS is so you can shut down the engine with the ignition key, the ksb provides a little timing advance, but the pump works regardless of the 2, if the fss is gutted. I believe that there is a fuel pickup in the tank that can fall off, if I remember correctly. The suddenness of the shutdown is what has me baffled...Mark

 

I tried each of my 2 tanks thinking they both won't lose a fuel pickup at the same time. I have an auxiliary tank in the bed that is used strictly for diesel. Every night before I get home, it gets switched to the diesel only tank to prime my lines, because my main tank uses veg oil/diesel mix.

The more I think about it, it might be the lift pump. I see one on Rockauto for $29, maybe I should change it out. Thoughts?

Thank you so much for getting back to me like this. It is nice to know there are good people out there willing to put their heads together. -Jeff

 

A few days after I got my truck, the lift pump failed. I couldn't start the truck with the starter, but it would start and run fine if I pull started it. This happened when it was cold and I thought I was having fuel jelling problems, but there was never any sign of jelled fuel in the lines or filter. A diesel mechanic friend told me to replace the lift pump (he gave me a used one to try) and it cured all of my problems. Before replacing the pump I'd disconnect the fuel line before the filter and see if it is pumping fuel.

 

It's possible the injector lines could be plugged where they come from the IP... If just a little fuel is coming from your 2 and 5 injector, I've never heard of an injection pump just 1/3 working but I couldn't say for sure.

 

By all means change the lift pump. I carry an extra in my tool box. While I would not think that a lift pump failure would cause such a sudden shutdown while the engine is running, it also wouldn't surprise me either. Occam's razor says that the simplest solution is usually the correct solution, words that I try to live by...Mark

 

Just had this happen to me. Had been running the engine about 15 min and drive to the corner and it died. Have been reading your suggestions. Last week, had trans oil changed and they found a leaking fuel filter, so they replaced it. Could that have anything to do with it dying?

 

Yes…Mark