Mitsubishi D2400 (Satoh Bull) Loses power/ won't achieve full throttle

[R Clement]

I have a diesel Mitsubishi D2400 that we've used for the last five years to power a large chipper and for mowing roads and trails. A few months ago we starting using it to skid small logs. (within the weight specs of the three point hitch) On the way home one day it started losing power and by the time I got home (about a mile) I had to put it in 1 Low Low to get up the incline of our driveway. I drained and cleaned the fuel tank, changed the fuel filter, blew out the fuel supply lines and put in fresh diesel(and of course bleed the air out of the fuel pump and lines). It still has low power and won't rev to full throttle. I'm not sure what to do next, any ideas? Is there a way to test the pressure of the fuel pump output? If so what is it supposed to be?

 

[Ilikeurtractor]

What color is the smoke when you try to "rev it to full throttle"? If it's a sustained black smoke it's probably a plugged air filter. If the smoke is clear then it's fuel restricted.

 

[R Clement]

Thanks, no black smoke, I cleaned the air cleaner just in case, no luck. I've done the easy stuff. I'm trying to figure out the next step.

 

[Ilikeurtractor]

My next step would be to crack each injector line, one at a time only, while it's running and see what difference it makes. You might need to run it a little faster than idle to keep it running. If it acts the same across all cylinders then I would think it would still point back to not enough fuel getting to the pump. If some cylinders seem different it could be valve problems/compression issues on the cylinders that don't seem to make much difference when you crack the injector lines.

 

[R Clement]

Ilikeurtractor, Thanks for the tip. I'll give it a try.

 

[Ilikeurtractor]

No problem. It's just another one out of the "easy stuff" bag of tricks that might help narrow things a bit. Of course, when it gets into faulty injector pumps and such the bag comes up a little short. Smoke characteristics are about the most helpful though for initial diagnosis. I was thinking you could have something like a broken governor spring or similar that would be difficult to diagnose w/o opening it up. I looked up a D2400 on tractordata.com but didn't seee a listing for it. Is it a two or three cylinder diesel?

 

[R Clement]

Ilikeurtractor, oops the 2400 was a typo its actually a 2300 a two cylinder diesel(Satoh bull equivalent). I feel a bit foolish. I had cleaned all the fuel lines on the dirty side of the fuel filter but not the clean side. As a last try before tearing into the fuel pump I pulled off the four inch piece of fuel line between the filter and the pump. Low and behold it was bad, I replaced it, and have been mowing like mad ever since trying to catch up. Runs like a dream again. Great little tractor! Thanks for all the helpful info.

 

[Ilikeurtractor]

Good to hear and glad it was easy to fix. Diesels are really cool that way. Usually it's either really simple or really hard with the hard stuff being rare. Gas engines tend to usually wind up with carburetor issues which can be a pain. Thankfully most automobiles run fuel injection now and all one really has problems with are the small engines that still utilize carbs. It will be great when even the small engines are FI hopefully some day. Have fun with the tractor!