D600 Cranking but not firing

jpswift1 · #1 03-10-2019, 07:06 PM

Hi everyone, I'm no stranger to gas engines, but I'm relatively new to diesels. I have a Kubota D600 and it would start right up and a idle and mid throttle it would start immediately and run great with no smoke or misfiring. At high RPM's it would miss and smoke. I ran it for a little while and then all of a sudden it puffs some black smoke and it smoothed right out and ran perfect. I idled it down and it ran perfect at idle, mid throttle, and then perfect at high RPM......it sounded great and was smooth as could be with no smoke, and it ran very powerfully. I was thrilled......until about a minute later when it died out.

Now I go to start it and it cranks and cranks and then tries to fire and puffs a little smoke, cranks and cranks, and then tries to fire, puffs a little smoke, but it will not run. It almost seems like it is only firing on one cylinder, but I have no idea. Could you diesel folks please help me out on what to look at as far as diagnosing this goes? I pulled the fuel line and I can tell that the fuel pump by the tank is spitting fuel up to the injector pump just fine, but it seems like something is going on with the injectors or the injector pump, but I don't know how to go about diagnosing this. Thanks in advance for your help everyone.

cooperino · #2 03-10-2019, 08:07 PM

Step one. Make sure your getting fuel to both cylinders. crack open the lines at injectors and visually see fuel spitting out when cranking.. When was the last fuel filter change done?

darkminion_17 · #3 03-10-2019, 08:18 PM

I ask a question, new owner or didja just get this?
All three cylinders on a kubota need fuel, how are the filters, fuel tank, shutoffs, and lines?

cooperino · #4 03-10-2019, 08:20 PM

My bad dark.. I didnt see d600. thought he had a 2 cylinder. Yes all 3 need fuel lol

jpswift1 · #5 03-10-2019, 10:44 PM

Quote:

Originally Posted by darkminion_17

I ask a question, new owner or didja just get this?
All three cylinders on a kubota need fuel, how are the filters, fuel tank, shutoffs, and lines?

I'm a new owner. The previous owner said it said it sat for a year, but everything he said should be taken with a grain of salt. The filter looks dirty and I don't think it was changed in a while, but when I pulled the line going into the injector pump, fuel freely flowed out as the fuel pump was working.

I think I'll drain the old diesel fuel out and put new filters on and blow through the fuel line with compressed air. I'll take the advice and crack open the lines at the injectors and see if anything is coming out.

I'm hoping the injector pump didn't go bad all of a sudden. Is it possible that injectors get clogged, just like jets in carburetors get clogged?

ol'George · #6 03-10-2019, 10:55 PM

I've heard of guys with cub kubota diesels having problems with the fuel lines allowing air into them, and air is a no-no with diesels.
Also your intent to flush the tank, replace filter and replace the fuel with fresh
and bleed system is a good one.

jpswift1 · #7 03-11-2019, 01:09 AM

Later this week it's going to be warming up outside so I'll tackle it then. I really appreciate all the help so far, guys! It's just so frustrating when the engine cleared up and was running like a top and then all of a sudden it just dies out. I'm still hoping the injector pump didn't die out suddenly.

Oak · #8 03-11-2019, 07:56 AM

If you get it running good with blowing the lines out. Remove the tank and flush it good with Dawn dish soap and a bunch of water. Then change all the fuel lines, tank bungs, fuel shutoff valve and both filters. Then you should be good to go. Make sure and bleed the fuel system at the injector pump too.

jpswift1 · #9 03-11-2019, 10:58 AM

Quote:

Originally Posted by Oak

If you get it running good with blowing the lines out. Remove the tank and flush it good with Dawn dish soap and a bunch of water. Then change all the fuel lines, tank bungs, fuel shutoff valve and both filters. Then you should be good to go. Make sure and bleed the fuel system at the injector pump too.

That sounds like a great idea. Do you think the injectors could clog up with crud just as easily as jets in a carburetor would on a small gas engine?

ol'George · #10 03-11-2019, 02:21 PM

Quote:

Originally Posted by jpswift1

That sounds like a great idea. Do you think the injectors could clog up with crud just as easily as jets in a carburetor would on a small gas engine?

Hopefully the filter (s) will prevent that.
I'm betting on air or moisture in the system along with crud.
Make absolutely sure if you flush/wash the tank out with water, it is DRY!