IH and/or diesel experts, help

I have an International 544 Hydro diesel. I bought it for the slow speeds needed for pulling a transplanter. I also use it with my corn planter and rototiller and a few other utility jobs. It has run well for the 4 years I've had it but began acting up this year. After running for a while it will begin running rough (like a gas engine missing). The rpms will bounce up and down 50 to 100 rpms. Occasionally it wil rev up for a second then settle back down. Today i was rotiling at about 1800 rpms and it ran good for over an hour. Then it started running rough,orse than usual jumping between 1800 down to 1500 or less rpms. It would recover quickly but then just as quick do it again. I finally lowered the throttle to about 1550 and it ran smooth and gradually began to build up speed as I rototilled. finally I pushed it back up to 1800 and it ran ok for another 1/2 hour then started running rough again. I finished and got back to the shed but it wouldn't run smooth fast.
When I transplant I run about 900 - 1000 rpms. Anything else I like to run 1800 or faster. This engine only has 1865 hours on it. So what are your thoughts? Fuel filters, governor, injectors, pump, air cleaner, something else? I'm going to start with the filters and see what happens.
Phil

Try new filters first- especially the fuel flitler--

Try after new fuel filters putting a 1/2 quart of automatic transmission fluid in the fuel. IHC told modot a few years back to do that in our diesel trucks. Dry fuel seems to be a problem.

change the fuel filters. if that does not help, time for a pump rebuild.

Philcase, My Allis did the same thing, I finally found a piece of gasket material in the fuel tank, blocking the fuel line. Change your filters, check the vent in your fuel cap and dont forget to ck your air filter. Good luck.

As the others said try a set of fuel filters. If you still have problems check for air in the fuel. They sell glass sight glasses to install in your fuel line (before injection pump) but you can make one with clear plastic hose and clamps. Use a flashlight when you get it running, makes air bubbles easier to see.
I'm not familiar with your tractor, if it has a transfer pump before the injection pump make sure you are getting a positive pressure to the injection pump.

Hello philcase,
It sounds as if the engine is not getting enough fuel
The fuel filters would be a good place to start.
Air getting in to the fuel will act the same way.
Once you changed the filters you'll know for sure.
Guido.

After you have determined for sure you do not have a fuel supply problem or restricted fuel return, you can blame the pump. It has a hydraulic governor with a check valve and if that check valve ball does not seat properly from wear or contaminents the poor old governor doesn't know what to do. We had lots of problems on the 706 with that pump when new as the filters were letting little hair like crap through from filter itself. Engines would just jump up some rpms then back down. Usually bothered when not doing any work. Then some developed check valve wear problems which required replacing head in pump.