2014 Komatsu PC 138 will not restart once engine is hot

[Michael Derouin]

I have a 2014 Komatsu PC 138 that will not restart after we've worked it a few hours. Cold starts are fine. We were told that it probably was the injector pump so, we changed it and, is still has the same issue. We have no codes telling us anything. When we try to restart it, the engine turns but doesn't fire.

 

[funwithfuel]

Any codes? What generation? -10? Post a pic of the serial tag. ALSO, VERY IMPORTANT, https://youtube.com/@repairsecrets
Our very own , JohnC has taken the time to help you help yourself. Excellent tutorials to help you navigate the display.

 

[Michael Derouin]

No codes. It is a PC138US LC Serial KMPTC245K01040241

 

[funwithfuel]

I think that might be your FOPS sn look on the boom side of the cab on the structure. Should be a tag there.

 

[funwithfuel]

So, let's get into the service screen. Monitor fuel pressure target and fuel pressure actual. If they are close, within a couple hundred psi, your fuel is probably ok. Since you say it's hard start warm, I'm thinking a sensor compromised by heat. Cam and crank sensor are the big ones. If the computer has no reference, it can't fire injectors.

 

[Reinis Zelneronoks]

Hello. Check hydraulic pressure after you worked for some while. Komatsu sometimes has a problem that pump is activated, starter cant get up to speed cous of the load from the pump. It should not be mor than 70bar/7MPa in neutral position

 

[Stevo618]

I have the same problem with my 2014 Komatsu 138-10. Did u ever resolve the issue?

 

[IDalibor]

Ujutro bager pali, par sati radi, na pauzi se ugasi, kasnije teško upaliti sve dok se opet ne ohladi.
Kada pukne blok, glavni razvodnik hidraulike ostane veliki tlak ulja u njemu odnosno drži pritisak na hidrauličnu pumpu koja optereti motor koji neće upaliti sve dok opet tlak ne padne. Česti problem, tvornička greška.

 

[Stevo618]

Does anyone have a fix for that? A valve that can release pressure? Rebuilt valve? Rebuilt pump?

 

[IDalibor]

Na žalost novi glavni "blok" razvodnik kod kabine koji nije jeftin ili polovan ispravan

 

[Joe H]

In the morning the excavator turns on, he works for a few hours, on the break he shuts down, later hard to get in on until he cools down again.
When the block breaks, the main hydraulic diluent remains a large pressure of oil in it or keeps the pressure on the hydraulic pump that burdens the engine that will not start until the pressure drops again. A common problem, a factory error.
----------------------------------------------
Unfortunately, the new main "block" distributor in the cabin that is not cheap or poloted correct

 

[Marcrus]

Does anyone have a fix for that? A valve that can release pressure? Rebuilt valve? Rebuilt pump?

Cap the ls line off to the pump and if it still does it back the PC valve out, other, and I would personally be leaning towards stuck injectors or excessive pump leak off, if it has 7000+ hrs on it I'd instantly be saying pump, once counterweight is off theres a block on the side of the engine check rail and pump leak off from there