Hi, I'm new this forum (new to dozers for that matter) I just acquired a refurbished Komatsu D31E dozer that is in fairly great shape. The problem I'm having is after working with the machine for about 45 min. to an hour (running great) the machine idles down on its own just as if you hit the decelerator pedal. Everything with the throttle cable linkage, and decelerator pedal seems to be fine. After feathering the pedal for a few min. idle will pick back up and run fine for a few min. and then same scenario. I let the machine sit over night and came back next day cranked just fine and ran again for about 45 min to an hour no problem then starts doing it again. (Also checked/changed air/fuel filters) Any input would be greatly appreciated, thanks in advance.
I would check the fuel system to start with. Check that your fuel tank vent is not clogged. Run with cap loose. Make sure you don't have debris in bottom of fuel tank blocking fuel line. Check that fuel line is not clogged or collapsing, blow it out. Check that return fuel line is not blocked. There is probably a tee with a ball in it that can get clogged. Hopefully it will be a simple problem.
Thanks g_man, yesterday I started from the tank and worked my way forward. Got to the priming pump and the fitting on the bottom had a screen in it that was stopped up. Bled all the lines and she fired right up. Thanks again.