Komatsu Dozer wont start

[KyleB83]

We have a D53-16 that cranks but wont start. I am getting diesel all the way up the fuel lines to the injectors. Even trying the gas soaked rag only gets it to run for a few seconds. I am leaning towards clogged injectors.. any tips or tricks to unclog them?

 

[Bob Rooks]

Komatsu is a Japanese dozer. You may have better luck in the Komatsu forum.
When is the last time you pop tested the injectors? Are you getting white or grey/white smoke from the exhaust?

 

[4570Man]

Komatsu is a Japanese dozer. You may have better luck in the Komatsu forum.
When is the last time you pop tested the injectors? Are you getting white or grey/white smoke from the exhaust?

It doesn’t make much difference. There isn’t much difference between any basis Diesel engine.

 

[Sawyer Rob]

Are you sure it's diesel and not water getting to the injectors??

That may sound like a stupid question, but I've seen it several times in the past...

SR

 

[RonMar]

Disconnect a hard line and remove an injector. Reposition the hard line so you can re-install the injector on the hard line outside the engine. Purge all the air from the hardline and crank the engine and see if the injector sprays. If it sprays, can you vary the ammount with throttle position? Check fuel quality as mentioned.

If it doesn't:
1. There is still air in the hardline.
2. The throttle is not high enough to allow the governor to deliver enough fuel to run.
3. The shutdown lever is not fully released and is preventing the governor from opening the rack.
4. The governor is stuck/jammed or the mainspring is broken and not letting the governor mechanism open the rack.
5. Injector plungers or pump assemblies have issues...

 

[MossRoad]

Moved the thread to the general parts/repairs forum. Left a re-direct in the Chinese tractor forum that will expire in a month. You'll probably get more looks over here than in that forum. Good luck with your repair and please continue the discussion....

 

[KyleB83]

there is white/grey smoke coming out of the stack when trying to start.. I did have some foaming at the injectors when I cracked those hard lines. They deffinately don't give you a ton of room to work in on these things. I need to find my crowsfeet so I can get the other injectors. I need to do some research on the priming pump, or whatever it is called.. I have fuel flowing freely into that, but nothing coming out.. Not sure if it is suction fed when the filter is feeding the injection pump. Tried to fill the fuel filter bowl with diesel, and bled the injection pump.. My father in law told me this morning he thinks it may have algae in it from sitting for 2 years. We just had the starter rebuilt, and have 2 brand new batteries on it, so I don't think its related to slow cranking, but it does sound a lot healthier when I cover the intake with a gas soaked rag. I really think I need to confirm the hard lines are getting fresh fuel, and not old stuff... but even if it was old watery fuel, wouldn't a few times running off the gas rag be enough to clear that out? I need to do some looking at the throttle as well.. it seems like it is stuck about halfway down at the engine, but the throttle lever has full range of motion.

Thanks for getting this to the correct forum and the advice

 

[Sawyer Rob]

... but even if it was old watery fuel, wouldn't a few times running off the gas rag be enough to clear that out?

NO, and I DO think it's the fuel that's the problem...

I would take a clean pail, take the line off the injection pump where the fuel enters it, and use air pressure in the fuel tank to push some fuel through, to see what you have.

SR

 

[KyleB83]

I tried that in a few places and had nice clean fuel... once before the primer pump, and again after the fuel filter, granted, I filled the filter so I was probably just creating another air pocket up there. I still think I should have fuel flowing through that primer pump when I pressurized the tank, shouldn't I? I can only get to 2 of the injectors at the top, but can get the hard line off all 4 at the injection pump. Had a brain fart yesterday when we were messing with it, and didn't keep bleeding the 2 injectors to clear out the few bubbles they had.

On a 4 cyl, would 2 injectors be enough to keep it running to self prime the other 2, or am I going to have to get another set of Crows feet for the last 2 injectors?

 

[Ortimber]

Is it cranking fast enough? I’ve had healthy diesel engines frustrate me and not start if the batteries are down a little or there’s a gremlin in the electrical system (bad ground). My dad’s little JD 350 dozer is one of those machines. It’s in great shape mechanically, but will not start if the cranking speed is just a bit slower than normal.

Also, check intake side and air cleaner. I once had a Komatsu D21 that also would not start. Turns out a squirrel had packed the air intake hose with dog food. I was close to pulling the injection pump before I figured it out.