L2850 engine died after starting and won't start again

[Keppie]

My Kubota L2850 has not been started for about 18 months . It has been parked and covered outside in a mild, mostly dry climate near Sacramento. After checking my manual for any start up tips (finding nothing), making sure the battery was up to par, and all external items and all fluids were OK - except I didn't check how much fuel was in the tank . I thought I had put in some fresh diesel and fuel conditioner when it was parked. I turned the key, waited a moment to heat the glow plugs and twisted the switch to start.

I was astonished that the engine fired up instantly. No misses, no smoke, just a nice high idle. (Wow, these Kubota's rock, I thought!) About T plus 60 seconds after launch, I was sitting there in the seat thanking my lucky stars when the engine sounded like it dropped into a low idle. I touched the throttle to increase the RPMs a bit, but the RPMs quickly dropped and the engine died. It sounded much like it had run out of fuel. A quick try to restart produced nothing except a brief sputter and some gray exhaust smoke. My fuel gauge is inoperative so I stuck a long flexible plastic dip stick down into the fuel tank and it came out dry as a bone. Where did my fuel go (or did I not add fuel as I thought I had)? Anyway, I put in a couple of fresh gallons of #2, played with the dog for 30 minutes, and then attempted to start the engine again. No joy. A couple of times it tried to start but nothing came of it other than the gray smoke puff.

The Workshop manual doesn't really address trouble shooting this particular problem even though it mentions the symptoms in the troubleshooting section. It didn't seem to act like air was in the fuel line system but even if it did, I don't know how one could bleed the air out of the system if the engine won't run for the minute the manual suggests.

Before I start pulling off the fuel hoses, does anyone have some suggestions as to how I should proceed to systematically troubleshoot this problem? A search of the forum posts did not turn up what I was looking for.

TIA for any and all suggestions.

 

[dex3361]

You will need to bleed the air out of the fuel system. I am not real familiar with your particular tractor. Basically you will need to purge the air from your fuel bowl or filter by loosening it and let it fill up to overflow then close.
Then loosen the injector lines at the head a turn or 2. Then crank the engine over a few times to purge the air out of the lines. When you dont see any more air bubbles tighten the injector lines back up and try to fire it up. It may take a few times to get all of the air out. Be careful not to overheat the starter by cranking to long. Crank about 10 seconds and let it cool a few minutes. Let us know what happens.

 

[Keppie]

Randall, thanks for your response. I don't know what you mean by "head". I can send you a scan of my fuel system schematic so you can name the part on my tractor that you are referring to. Or, here is a description: Fuel flows in a single line from the fuel tank through the fuel filter to a fuel transfer pump to the injection pump. At the injection pump at the point where fuel enters the pump, there is an air vent cock (which can only be used when the engine is running) to bleed air from the lines. From the injection pump, there are four high pressure lines that go to each injector. These lines are secured at both ends by compression nuts (it appears). These lines are all secured by hardware to keep them rigidly in place. In addition, there is a fuel overflow line that returns excess fuel from the injectors to the fuel tank. There is an air vent fitting on the fuel filter to which a line is attached to return the air in the fuel to the fuel tank to prevent the engine from stopping or running irregularly.

I hope this helps you and anyone else viewing this thread to suggest possible solutions to my no start problem.

 

[dex3361]

Randall, thanks for your response. I don't know what you mean by "head". I can send you a scan of my fuel system schematic so you can name the part on my tractor that you are referring to. Or, here is a description: Fuel flows in a single line from the fuel tank through the fuel filter to a fuel transfer pump to the injection pump. At the injection pump at the point where fuel enters the pump, there is an air vent cock (which can only be used when the engine is running) to bleed air from the lines. From the injection pump, there are four high pressure lines that go to each injector. These lines are secured at both ends by compression nuts (it appears). These lines are all secured by hardware to keep them rigidly in place. In addition, there is a fuel overflow line that returns excess fuel from the injectors to the fuel tank. There is an air vent fitting on the fuel filter to which a line is attached to return the air in the fuel to the fuel tank to prevent the engine from stopping or running irregularly.

I hope this helps you and anyone else viewing this thread to suggest possible solutions to my no start problem.

1) Loosen your fuel filter so that gravity fills it up to overflow.

2) Tighten fuel filter

3) Loosen the air vent cock on the injector pump and crank the engine with the starter until you see no more air coming out of the air vent cock. ( you may try to start the engine because this may be enough to allow it to start if not keep going)

4) Close air vent cock.

5) Loosen the compression nuts on the four high pressure lines at the injectors a few turns, then pull on the tubing to unseat the tube.Crank the engine till fuel spurts out and the air is purged (be careful of the spray possibility).

6)Tighten the compression nuts.

7) Try to start the engine. If it fails repeat the process.

If this fails send a schematic for review and by the way it was an excellent description of the fuel system.

Let us know haw it turns out.

 

[rbargeron]

The only thing I'd add is when loosening the compression nuts, loosen them only a half turn. That way the fuel won't spray as far. Tighten them while cranking - it will probably start and go.

 

[sandman2234]

When it does get started, it will probably run extremely rough until all of the air is worked out of the system. Just bear with it, keep it going and don't try to work it until it smooths out.
David from jax

 

[Keppie]

Thanks to Randall, Dick, and David, my L2850 is running smoothly again.

I really appreciated all the suggestions.
Here's what I did and it worked. These are the steps that Randall provided with my annotations.

1) Loosened the fuel filter so that gravity filled it up to overflow. (it seemed full but this step made sure it was)

2) Tighten fuel filter

3) Loosen the air vent cock on the injector pump and crank the engine with the starter until you see no more air coming out of the air vent cock. ( you may try to start the engine because this may be enough to allow it to start if not keep going)

I hooked up my Hvy Duty charger to provide help for the battery. Set it for the 200 Amp "Start" position and hit the key starter. This power really spins the engine. After three intervals of 10 seconds of starter followed by 10 seconds of rest, the engine nearly started on the fourth cycle. On the fifth cycle it started and actually began running smoothly. (you were right, Randall) I doused the 200 Amp charge, let the engine run about a minute , closed the air vent cock, and let her run another five minutes (or so) until the low idle kicked in. Shut her down for 30 minutes, checked fluids again, at she started right up, let it run until it hit operating temp. All was well.

4) Close air vent cock. (done as noted above)

These notes are going into my manual.

Now that things are back to square one, thanks to the list members, please go to my other post and let me know your thoughts on that. It is "L2850 Front Axle leak and repair question". I gotta get this tractor moving!

 

[simonmeridew]

this thread is an excellent refresher on what to do when your diesel runs out of fuel, and the specifics can be custom modified for the various diesel models. This stuff is in the operators manual to some extent, but sometimes saying the same thing another way makes it real.
simonmeridew

 

[Egon]

Its good to see the fellows gave you information to get you up and running.

With my B7100 I always had the two sized wrenches for bleeding in the tool box as I regularly ran it out of fuel to check the bottom of the tank for debris!

 

[sandman2234]

Egon,
Ever find anything in the bottom of the tank?
I am always too mad at myself for not getting fuel sooner, so I forget to check for thing in the bottom of the tank.
David from jax