One time start leading to stalling and sputtering out, now won't start at all

FoxtailM

New member

Equipment
Kabota L2501
Feb 6, 2025
2
3
1
New York State
Currently attempting to troubleshoot starting problem with our L2501 after running into issues during a winter start. Tractor has been kept in a covered shed with minimal exposure to the elements other than cold temperatures (this is in upstate NY, so consistently below 30 with a few days in the negatives). A few days ago we tried to get the tractor running, successfully started, but engine was weak and sputtering. Potentially due to my own inexperience, I had hoped that getting the tractor to move may help improve the circulation issues and so attempted to drive it (after letting it idle for a few minutes), but it only went around 50ft before sputtering, then stopping completely. Now the engine will not start at all, or even turn over. The battery is still working, and the starter will attempt to crank, but there is no other response from the engine, and our best guess is that fuel is not getting through.

Reading through online forums and guides, as well as the owners manual, my current best guess is that the issue could be coming from air in the lines or engine. When the issue first manifested, we assumed it was gelling in the fuel filter, and so removed it from the tractor in order to thaw it. My father has done this before and was the one guiding the process, however he never had us bleed the fuel line after reconnecting the filter, which I have since learned is an important step. Kubota says that the line should be bled by loosening the air-vent-shutoff-valve and starting the engine, but since our engine won't start at all, this isn't accomplishing anything. I've been attempting to limit my troubleshooting efforts in order to avoid causing further issues.

In case it wasn't obvious, we are both a little inexperienced when it comes to diesel engines, and I am learning from this process that we have definitely made some mistakes in how we have treated this machine, which I'm attempting to learn and rectify. In case it helps with troubleshooting, the tractor has not been kept with a full fuel tank, and is currently low on coolant. We also did attempt to charge the battery but with no success. Any advice for troubleshooting, or general winter care advice, would be greatly appreciated
 

North Idaho Wolfman

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Now the engine will not start at all, or even turn over. The battery is still working, and the starter will attempt to crank, but there is no other response from the engine, and our best guess is that fuel is not getting through.
WARNING: DO NOT use any starting fluid or ether on this engine!

Let's clear up a few things as your using terms that are counter dictory.

Will the engine crank, turn?
Yes move on, No then you have something stopping it from cranking.
let us know the motor is not turning then we can go down that route.

If it's cranking, lets find out where it's getting fuel or not getting fuel.
Pull the bowl off the filter, is it full of fuel?
If not then pull the input line off the filter housing, is there fuel coming out?
If there is fuel does there appear to be any water or ice in the bowl or filter?
If yes remove the filter and replace and put the bowl back on wait a min or so and pull the bowl back off Is there fuel?
If yes move on if no then go back up and read remove the line going into the filter housing.

So if you have fuel in the bowl and the bowl is nowe back on, move on down.

1738864950180.png


Go to the side of the injection pump and locate the jet start valve (red below)
Remove the small hose coming off of the valve, turn the valve to open it CCW, crank the tractor.
Are you getting fuel out of the valve?
If you are then close the valve and put the hose back on.

Give us your answers

1738865025471.png
 

FoxtailM

New member

Equipment
Kabota L2501
Feb 6, 2025
2
3
1
New York State
Thank, this is all really good to know. I started following your troubleshooting, but then ended up getting it working almost immediately. I think the issue had been air in the system because I had left the air-vent-valve open and it ended up kicking out smoke and running the next time I tried turning it on, I'm guessing I just hadn't let it run long enough immediately. Let it warm up, took it for a quick drive, and all seemed to be working well.

Apologies for the poor use of terminology/contradictions, this was all stuff I'd learned after a 24 hr research session trying to learn the system enough to diagnose it. This tractor doesn't actually belong to me, it's my fathers, and this is my first time really working on it, or any diesel system. I Appreciate your response and level of detail though, and this has been a real inspiration to dig into this more and better educate myself about these systems.
 
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Russell King

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Jun 17, 2012
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You need to be sure the fuel is treated for the temperature the tractor is seeing. Often the tractor is stored in late summer with fuel purchased in the summer that gels in the winter.

That will lead to more problems just like you just experienced.
 
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RCW

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Apr 28, 2013
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You need to be sure the fuel is treated for the temperature the tractor is seeing. Often the tractor is stored in late summer with fuel purchased in the summer that gels in the winter.

That will lead to more problems just like you just experienced.
I see @FoxtailM is in New York State. Not sure where in NYS, but I've seen -12F recently.

Understand leaving the inadvertent bleed valve open caused some problems.

Properly treating your fuel is important. I would have guessed you gelled it pretty solid.

Glad you got it going. (y)