Mitsubishi 4 cylinder diesel stalls after being run for 30 minutes

[bcribb]

I have a 4 wheel drive tractor with a bucket loader and backhoe attachment.. It has a 39 hp Mitsubishi diesel engine.. I've just had the injectors checked and replaced , new electric fuel pump , new hose from tank to fuel filter assembly, new fuel filter.. Blew air back into tank from filter to clear any clogs. Put a clear fuel hose at the supply of the injector pump to see if I was getting good fuel and no air.. Seems to be ok.. Put a clear fuel line from the fuel injector rail where it goes back to the tank.. I'm getting fuel there but it looked like a lot going back to the tank so I put a wire tie around the hose and restricted the flow a little but that didn't make any difference as far as the stalling.. Should I take the tie wrap back off?? I've checked compression, seems ok, tractor cranks up better since I've replaced the injectors and 1 glow plug that was bad.. It almost seems like its running out of fuel when I'm going up a small incline, this is after its warmed up.. The previous owner had the same problem and that's probably why he sold the tractor.. But I don't won't to sell it I want to figure this thing out.. The injector pump is small and easy to remove but I wanted to get some more ideas before I removed it.. The pump has 4 lines and works off the cam.. Not sure about the governor how it should work on this tractor.. I thought when the load was bigger the governor would take the rpms up to a higher rev.. Also has good clean fuel.. Was told to put a little motor oil in with the fuel for better lubrication.. If I run the rpms up high it seems to do better but shouldn't at a lower rpms it still not stall going up a small incline.. Any help on this issue will be greatly appreciated.. I like my tractor

 

[Tx Jim]

Have you checked to be sure fuel tank is venting IE try operating with fuel cap removed.

 

[hutchman]

Ditto what TX Jim said. I had a John Deere do that to me and it turned out to be the little bobber thing on the fuel cap that vents was stuck instead of venting. It would run for a while and quit. Changed filter ... same thing.

Didn't figure out the problem until I got mad and put my mouth on the line from the tank and blew air and it presurized the tank and shot fuel about into my face.

 

[PILOON]

Have you checked to be sure fuel tank is venting IE try operating with fuel cap removed.

Gotta agree with this diagnostic as well due to the 30 min accumulated time frame.
Anything else would be closer to instantaneous stopping.

Another might be an internal tank particle filter screen. Blowing air backwards would clear that temporarily.

Also keep a close eye on that clear tubing as fuel has a habit of corroding some plastics with nasty results.
For one it can go hard rapidly and possibly even dissolve certain types gradually.(injectors might not like that)
Best to stick to fuel line material.

 

[skyhook]

Yes, i would take the tie wrap back off, this unused fuel has to go somewhere.
As the others have said, check the venting first, with the electric fuel pump, I don't think your running out of fuel for the pump, although depending on the hours of your machine,, a worn out injection pump will produce those symptoms when it gets hot. (metal expands when heated) and these pumps have tight tolerances.
If your still in touch with the previous owner, ask him if he ever pressure washed his engine,
hitting a warm injection pump with cold water is a no, no. Just thinking out loud here.

 

[bcribb]

I'll check the fuel cap today and make sure its venting.. I'll let you know if that solved the problem.. Thanks for the help. Barry

 

[bcribb]

I'll take the tie wrap back off and check to see if the tank is venting as well. The clear tubing is a gas/diesel grade material so it should be ok.. Thanks for everyone sharing their experiences with this problem.. I'll post back later to give results..

 

[bcribb]

I loosened the fuel cap today and it ran good today.. Crossing my fingers that the problem will be solved by doing a little work to the fuel cap.. thanks for everyones input on my problem.. Happy camper today