Komatsu Excavator PC200-LC6. S/N close to A82500. Ran fine one day. Wouldn't start the next. You can crank and crank. No smoke. Acts like a bad fuel shutoff solenoid but from what I can tell this engine doesn't have a shutoff, just a throttle motor. Is this correct? No error codes. I suspected possible animal damage to the wiring since a bunch of the foam inside the engine compartment was recently chewed off but I couldn't find any damaged wires. This has the 4- and 3-wire plugs at the throttle motor. If you unplug these, E05 appears but it disappears when you plug back in the wires. Fuses are all OK. Obviously I also re-bled the fuel system and there seems to be plenty of fuel supplied to the system. Any help in diagnosis would be appreciated.
Below is a snip from the parts manual (A82001 thru A83000) that show there are 2 electric shutoff valves offered, depending on what brand of injection pump is on the engine.
To test the solenoids without removing them.. Run a jumper wire from the battery + and just touch the terminal on the solenoid.. you should hear it click. IF IT DOES.. try to start it while holding the jumper to the terminal.. IF IT STARTS while holding the jumper.. remove it and see if it shuts down.. if it does.. you have lost power to the solenoid and its time to check fuses/relays. OR just break out the meter and SEE if your getting voltage TO THE SOLENOID TERMINAL.. I've seen voltage drop off while cranking also.. so check it while trying to start too..
Thanks! Got it going. It was so simple it was stupid. Something chewed the solenoid wire and pulled the connector right off the solenoid. The chewed up foam lying on top of the injector pump should have given me a clue. I got all screwed up from the beginning at the Komatsu parts book website as the machine is really a 6LC, not an LC-6 and I couldn't find a solenoid drawing. Then in years past there was some extra curricular wiring in the area for some kind of an add-on glow plug so there were old wires that I got confused with the chewed stub of the power wire for the solenoid.