Deuce ran for 20 min then quit wont restart for days then repeat all over

[Havasurat]

M35a2 LDT-465-1D

Have replace all fuel lines including the one in the tank. Have replaced all fuel filters twice. I have 8 psi coming from the intake pump. See pictures for timing marks and valve position.
The injector pump is freshly back from Overhaul. This has ran a total of 20 minutes at idle then when we went to drive it. We only made 1/4 and it quit like we slowly starved it of fuel. It pulled 2500 rpm no problem in 1st, and 2nd gear died after shifting into 3rd. Towed it back rechecked the system for air found nothing. Got it restarted for about 5 minutes. Nice clean looking exhaust then it shut off like I pulled the shutoff valve.

 

[cattlerepairman]

There's a troubleshooting flowchart in the TM.
Pressure from the lift pump is good but is it sustained? Gunk in the tank clogging the pickup? Soft in tank rubber hose collapsing? Vent issue? The fuel filler cap is unvented. Perhaps the tank vent line is clogged.

 

[Havasurat]

I will have to check the vent line. I have not done that one. I replaced the intake rubber hose all ready. I ordered the Parker fuel pump today. What TM number? please

 

[Jeepsinker]

Make sure the copper fuel line isn't crushed flat anywhere between the tank and the injector pump fuel intake. Also, where it goes through the frame and makes a sharp turn coming from the tank, the line can get crimped closed right there from being bent when removing the lift pump.

 

[daytonatrbo]

Symptoms remind me of a scooter I had as a kid. I put a brand new fuel filter on it and it would run me about 2 miles down the road before it quit. It would always restart after waiting at least 20 minutes. Turned out the new filter had an issue and wasn't flowing enough to keep the bowl full in the carb.

 

[Havasurat]

The truck is currently rigged with all brand new fuel lines from the tank to the pump and from the pump back to the tank. That was done as part of this trouble shooting.

 

[Jeepsinker]

Ok, we'll it looks like you are pulling fuel through the filters faster than they can flow. The new hose you put in the tank may be collapsing under vacuum. I don't know what kind of hose you used in there. Otherwise, you must have a filter issue like mentioned above. Or you may have gotten a piece of debris or something inside a connection that you didn't notice while putting the new lines on.

On another note, have you checked your fuel pressure at the final filters? You can use a cheapo manual oil pressure gauge plumbed into the bleeder port in place of the bleed screw. You should see at least 25 psi at idle and 40-60 psi under throttle. Reason I mention that is your booster pump could be acting stupid.

 

[Havasurat]

I will rig up a fuel pressure gauge on Monday and check. I have a very thick walled immersion rated line in the tank. That was also installed as part of the trouble shooting. I will pull all of the line on the IP and check for debris.

 

[Jeepsinker]

Will it restart when the motor is still hot?

 

[Havasurat]

No it will not. I have not been able to restart it scince I started this thread and that includes trying it after every item I have changed. About ready to swapout the new IP. If the new pump when I get it does not help me out.

 

[Jeepsinker]

Don't swap the pump. Pull the hydraulic head. If the button and retainer on the bottom has fallen off, there is your problem. If not, your hydraulic head has $hit the bed.

 

[Havasurat]

The shop that rebuilt it has offered to do free swap out. But i can check the head.

 

[Jeepsinker]

Yeah, it is just easier to fix the HH than to change the whole pump. When these pumps get rebuilt, they don't get a new or rebuilt hydraulic head, so it is entirely possible that your head is bad.

Are you familiar with the removal and installation procedures for the head?

 

[Havasurat]

I have not ever taken one apart.

 

[Jeepsinker]

Ok. Pull the shutoff cover off ( the two screw cover where the shutdown cable connects), there you will see the shutdown lever with a two screw, safety wired bridge plate holding it in. First, make sure that lever moves freely. You'll be removing it whether it moves freely or not. When you pull it out be very easy and careful, there is a little hammer shaped tit on the end that can fall out and be lost. You also have to remove the small Jesus clip holding the governor rod onto it.
Once that is out you should be able to see a gear behind it and a pointer cast into the aluminum. Put your transfer case in neutral and the transmission in gear and use a pry bar on the jackshaft to turn the motor until the red (or scored) tooth lines up with the pointer. Then just remove lines and the four hold down nuts and pull it up and off. It should come out very easily. If it doesnt, do not force it, sometimes the mark needs to be lined up just a hair before or after the pointer for the head to come out, so readjust it and try again.