Combines R52 losing power lube pump badIJ

Had a 52 years ago with same problem. Pulled the injector pump and the arms on the governor in the pump were worn unevenly and were throwing the governor off balance. It only cost about $350 to repair. Diesel shop said they have had more problems on Deutz than other engines with R. Bosch pumps. We didn't mess around fuel timing the pump like the book says. We just used fingernail polish to mark the pump before removing.

either something is blocking the tank outlet line , (some have been inadvertently reversed with return) the fuel lines, water separater filter down on the side or the filter at the eng. Ususally something in the filter area at lowest point. If it were the pump - it would not run then get weak.

Don't overlook charge check valve on fuel return line out of fuel pump. I hadn't had one fail on these engines and somewhat doubt this is your problem but they need to hold charge pressure in main pumping area of diesel pump or you may lose power. I've seen where junk is in these on other engines so they lose charge pressure and some have the weakened or broke spring so they don't hold sufficient charge pressure continuously.