Kubota start then die issue. Possibly electrical???

[Rosgood14]

2005 Kubota L4300DT with only 200hrs on it.

Figured I’d ask you folks here and maybe one of y’all have had a similar issue

Tractor was running and starting perfectly without any issues. Did a lot of brush hogging on some pasture and wooded areas and had no issues. Came out the next day to start and it would fire up and die immediately. Did this several times and I finally realized if I kicked it back to the pre heat glow plugs, it would run for a few seconds and I kept doing it repeatedly quickly (yes I know it’s not good but gotta run the tractor) and it would finally stay running. Takes me 2-3 times of doing this before I can kick it over to run and it stays running usually. Once running it has zero issues. I have a video of me doing this but I guess we can’t post videos on here.

Also I’m in south Texas so it ain’t cold so I don’t think it would be the glow plugs and don’t have any fuel leaks that I can find and I checked all fluids, cleaned all electrical connections including the key switch, and cleaned the air filter. So I’m a little baffled and any help would appreciated and yes I’m very mechanically inclined just not electrically inclined

 

[jaxs]

2005 Kubota L4300DT with only 200hrs on it.

Figured I’d ask you folks here and maybe one of y’all have had a similar issue
I’m very mechanically inclined just not electrically inclined

I'd begin with making sure kill leaver on pump is moving full stroke.,solenoid might be malfunctioning. If you have both electric solenoid and manual pull knob,disconnect electric solenoid until this problem has been nailed down. You might even disable solenoid and operate lever by hand at the pump.
If there's no problem at kill lever crack fuel line between lift pump discharge and injector pump intake to see if there's pressure when key is on. If low or no pressure it can't hurt to change filter before condemning pump. Next step is putting pressure guage on injector pump or cracking lines at injector, CARFUL THE PRESSURE IS HIGH ENOUGH TO CUT SKIN OR POP AN EYEBALL. See what that turns up then report back.

 

[Rosgood14]

I'd begin with making sure kill leaver on pump is moving full stroke.,solenoid might be malfunctioning. If you have both electric solenoid and manual pull knob,disconnect electric solenoid until this problem has been nailed down. You might even disable solenoid and operate lever by hand at the pump.
If there's no problem at kill lever crack fuel line between lift pump discharge and injector pump intake to see if there's pressure when key is on. If low or no pressure it can't hurt to change filter before condemning pump. Next step is putting pressure guage on injector pump or cracking lines at injector, CARFUL THE PRESSURE IS HIGH ENOUGH TO CUT SKIN OR POP AN EYEBALL. See what that turns up then report back.

I don’t have a manual kill lever on this tractor (not that I’ve found). It’s just a regular key switch on and off. I will try changing the fuel pump but I honestly don’t think it’s a fuel issue, because it runs perfectly it just doesn’t want to stay running upon initial startup but once running after a minut or two it runs without issue.

 

[Russell King]

Look on line for the parts diagrams

Kubota Tractor Corporation - Illustrated Parts List

- K-PAD - Parts Lists - Illustrated Parts Lists - diagrams

apps.kubotausa.com

I believe every tractor has a manual way to stop the diesel engine when the electric method fails.

 

[whitetiger]

I don’t have a manual kill lever on this tractor (not that I’ve found). It’s just a regular key switch on and off. I will try changing the fuel pump but I honestly don’t think it’s a fuel issue, because it runs perfectly it just doesn’t want to stay running upon initial startup but once running after a minut or two it runs without issue.

Depending on the actual model number and engine serial number will dictate which style of shut-off your tractor has.

 

[jaxs]

I will try changing the fuel pump but I honestly don’t think it’s a fuel issue,

Whoa,hold up there. I never intended to suggest replacing pump or anything else unless tests reveal the need. Half of finding what's wrong is finding out what ISN"T WRONG.

 

[Rosgood14]

Whoa,hold up there. I never intended to suggest replacing pump or anything else unless tests reveal the need. Half of finding what's wrong is finding out what ISN"T WRONG.

Sorry did not mean fuel pump but meant fuel filter.

 

[Rosgood14]

I'd begin with making sure kill leaver on pump is moving full stroke.,solenoid might be malfunctioning. If you have both electric solenoid and manual pull knob,disconnect electric solenoid until this problem has been nailed down. You might even disable solenoid and operate lever by hand at the pump.
If there's no problem at kill lever crack fuel line between lift pump discharge and injector pump intake to see if there's pressure when key is on. If low or no pressure it can't hurt to change filter before condemning pump. Next step is putting pressure guage on injector pump or cracking lines at injector, CARFUL THE PRESSURE IS HIGH ENOUGH TO CUT SKIN OR POP AN EYEBALL. See what that turns up then report back.

I'd begin with making sure kill leaver on pump is moving full stroke.,solenoid might be malfunctioning. If you have both electric solenoid and manual pull knob,disconnect electric solenoid until this problem has been nailed down. You might even disable solenoid and operate lever by hand at the pump.
If there's no problem at kill lever crack fuel line between lift pump discharge and injector pump intake to see if there's pressure when key is on. If low or no pressure it can't hurt to change filter before condemning pump. Next step is putting pressure guage on injector pump or cracking lines at injector, CARFUL THE PRESSURE IS HIGH ENOUGH TO CUT SKIN OR POP AN EYEBALL. See what that turns up then report back.

Well I replaced the shut off solenoid and the key switch (some others said it may be the culprit) and still doing the same thing. I have a fuel filter coming in tomorrow but I just find it hard to believe it is fuel related because the tractor runs flawlessly once i get it cranked. Just the initial startup that’s is killing it. Also I have yet to locate the manual kill lever you spoke of. My last tractor had one but this one does not that I can find.

 

[jaxs]

Well I replaced the shut off solenoid and the key switch (some others said it may be the culprit) and still doing the same thing. I have a fuel filter coming in tomorrow but I just find it hard to believe it is fuel related because the tractor runs flawlessly once i get it cranked. Just the initial startup that’s is killing it. Also I have yet to locate the manual kill lever you spoke of. My last tractor had one but this one does not that I can find.
[
You need not be ashamed you don't know how to maintain your tractor but you should take stock of your willingness to pay attention,follow instructions and learn before asking others to teach you. You are hung up and arguing about the very first thing you were told in the first sentence of first response 4 days ago and shown a picture of in post #4 three days ago. I can't stake my life on your tractor having a lever that kills engine but I'll stake my reputation the tractor had one from the factory as pictured in upper left corner between screws numbered 140 and I'll wager 3 to 1 the lever is still present. What do you call that thing that is pushed and pulled by the solenoid you replaced on the advice of "some others"? Troubleshooting is a step by step process of testing,not helter-skelter parts replacing. As for your certainty the problem is electrical, it might be but it requires less time and money using an organized process to find out than acting on guesses. Your tractor will start and run without a battery so don't become engrossed by electrical doo-dads. You might consider that harsh but not near so much as when my elementary teacher slapped me before telling me to set up straight and pay attention or allow her to set in my seat while I teach class. So do you want us to help you figure out what's wrong or question our advice?

 

[Rosgood14]

I honestly don’t know who you are talking to grown men on here like they’re idiots. I do in fact know how to maintain my equipment and work on my equipment and I work on equipment you probably wouldn’t even understand for a living. So before you come on here being an asshole why don’t you try asking if I have checked the other things listed such as the fuel pressure as you stated. The fuel pump does not run with the key on as you implied I should try because it is a manual fuel pump driven by the motor not an electric pump. Plus if the pump was going bad it would not run perfectly once started. I have also found the kill lever which is doing its job properly if pulled. You can’t disconnect the solenoid one because it won’t allow the tractor to start. On a last note, as I’m sure your elementary teacher im sure taught you, if you don’t have anything nice to say, then don’t say anything at all. Thanks and have a great day.

 

[D2Cat]

I am not familiar with your specific tractor, but the first thing that comes to mind is the shut off solenoid.

Kubota used a couple of different types. Some had two solenoids (in one container). One circuit was used to start the engine, the other one was then activated when the key switch was returned to RUN. This side of the solenoid is what seems to not be working in you situation. As soon as you release the key the engine shuts off. That says they side of the solenoid is not holding it's position for the engine to keep running.

 

[D2Cat]

That solenoid is what is causing the frustration. The engine starts and runs, then doesn't stay running.

 

[D2Cat]

Here's a thread that may help. https://www.orangetractortalks.com/forums/threads/l3400-hst-fuel-solenoid-problem.53908/

 

[GreensvilleJay]

It could be the fuel filter. Partially clogged, it can't pass enough enough fuel to start and run due to the mechanical pump. Once going, pump can suck fuel through the filter.
While it doesn't have a lot of hours, old fuel filter could have black algea(??) or 'crud' in it from sitting over the years.
At least a new filter is a good move !!

If possible, remove fuel hose from lift pump to injector pump, add a line to a small pail,then crank the engine for 15-20 seconds. You should see a good pulsing flow of diesel into the pail.

 

[Rosgood14]

Here's a thread that may help. https://www.orangetractortalks.com/forums/threads/l3400-hst-fuel-solenoid-problem.53908/

I replaced the solenoid 2 days ago and still doing the same thing.

 

[Rosgood14]

It could be the fuel filter. Partially clogged, it can't pass enough enough fuel to start and run due to the mechanical pump. Once going, pump can suck fuel through the filter.
While it doesn't have a lot of hours, old fuel filter could have black algea(??) or 'crud' in it from sitting over the years.
At least a new filter is a good move !!

If possible, remove fuel hose from lift pump to injector pump, add a line to a small pail,then crank the engine for 15-20 seconds. You should see a good pulsing flow of diesel into the pail.

Removed the fuel line from the pump and it does have a steady pulsing flow like you stated. Could it not be enough, possibly but won’t know if it’s the filter until it comes in. Honestly don’t think it is because if the filter was even partially plugged, I don’t think it would run good especially at high rpm’s when I’m brush hogging.

 

[D2Cat]

Be sure you got the correct solenoid. They pretty much look the same from the outside.

 

[Rosgood14]

Be sure you got the correct solenoid. They pretty much look the same from the outside.

It was an exact match, part number and all

 

[D2Cat]

Might check power at your ignition switch and solenoid to see if power is getting to that solenoid when in the RUN position.

 

[D2Cat]

Did you get it figured out?