My Komatsu pc78uu will start fine then shut down after 3 seconds. No error codes or warning lights and no fuel issue. any ideas? Thanks
it sounds like your pump is stuck stroked up so as soon as it starts to build pressure it overwhelms the engine and shuts it down.
You should probably describe what you mean by "shut down after 3 seconds." Does the engine stop like you turned off the key or is it lugged down like the pump is pulling more horsepower than it can put out. In one case you likely have an electrical issue in the other a hydraulic issue.
I just had the same problem with a pc78us-6. The problem was the fuel pump solenoid.
Yea shuts down like you turned off the key, did it first whilst I was operating it normally, it just cut out for no reason like it was switched off
Thanks, do you mean the stop solenoid or is there another one?
Thanks for the replies, I've narrowed it down to the stop solenoid, if I hold it in position it stays running, now have to work out if it's the solenoid itself or something telling it what to do
The thing about those sol. is> they MUST BE adjusted properly.. IF its not sitting ALL THE WAY closed w/ voltage applied, it'll release.. {or open, depending on how u wanna look at it} Lets just say it must be SEATED ALL THE WAY.. You can take it apart & clean the inside bushing.. it gets gummed-up.. then zip tie the bellows back on. I cant believe how inexpensive the replacement is..!!! The same "type" for a Cummins would be 300.00.
Same problem with Volvo EC140, problem was with fuel solenoid, coil for holding was burned, I bay new one but it stroke mast be adjusted properly. Regards, Milos
EC 140 used deutz engine D4D I believe. It's easy to put the solenoid in wrong. You need the service manual for this procedure. You can damage the rack. Good luck. Back to OP, glad it was a simple fix.