KUBOTA L3430 HST KEEPS CUTTING OFF

[RNP]

My Kubota L3430 HST keeps cutting off and will not run continuously. I have to turn the ignition switch off; turn it back on and wait for the unit to click before it will restart. I blew out the fuel tank and lines, but that did not help. What is the likely problem? The local Kubota maintenance shop was no help. This has been going on for nearly 2 years. Can anyone recommend a solution?

 

[North Idaho Wolfman]

Will it not crank yet not fire?
Or will it not crank?

It's sounds like it's setting the stop solenoid and your waiting for it to cycle off before it will run.
The way that system works is that the switch powers a timer and when power is removed from the timer, that timer powers the stop solenoid on for approximately 5 seconds then shut off.
It could be a connection issue inside the switch or a wiring issue from the switch to the stop solenoid timer, or could be the timer itself having the problem.

The WSM will be your friend here on troubleshooting the cause.

 

[Workerbee]

The click you here is likely the relay for the glow plugs. It would seem you have a fuel supply issue. Is the shutoff on the pump functioning correctly?

 

[RNP]

Will it not crank yet not fire?
Or will it not crank?

It's sounds like it's setting the stop solenoid and your waiting for it to cycle off before it will run.
The way that system works is that the switch powers a timer and when power is removed from the timer, that timer powers the stop solenoid on for approximately 5 seconds then shut off.
It could be a connection issue inside the switch or a wiring issue from the switch to the stop solenoid timer, or could be the timer itself having the problem.

The WSM will be your friend here on troubleshooting the cause.

OK...I'll check the WSM.

Thanks

 

[RNP]

OK...I'll check the WSM.

Thanks

It cranks well...runs a little...cuts off. After a little wait or a clicking gyration...it'll crank, run etc. Sometimes it will run for a short while...sometimes a long while...then it cuts off.

 

[RNP]

The click you here is likely the relay for the glow plugs. It would seem you have a fuel supply issue. Is the shutoff on the pump functioning correctly?

I'm not sure if it's functioning correctly. It shuts off untimely. I don't think it's the shutoff...because I installed a new shutoff and it functions the same.

Could it be a fuel pump issue?

 

[North Idaho Wolfman]

It cranks well...runs a little...cuts off. After a little wait or a clicking gyration...it'll crank, run etc. Sometimes it will run for a short while...sometimes a long while...then it cuts off.

Does it cut off instantly, like you shut the key off or slowly bog down and stall?

 

[RNP]

Does it cut off instantly, like you shut the key off or slowly bog down and stall?

Sometimes it shuts off instantly...sometimes it'll start to cutoff, the rpm drops, then it will start going again. It is not consistent as to how it does.

 

[RickDebacker]

Sometimes it shuts off instantly...sometimes it'll start to cutoff, the rpm drops, then it will start going again. It is not consistent as to how it does.

I'm confident that you've solved your problem by now, but for the next guy browsing here, this sounds EXACTLY like the problem I just had. It ended up being micro organisms in the fuel which once I blew it all out and replaced the filter, still ran the same. The key was bleeding the air from the fuel system which is simple with these tractors. You simply remove the RH lower engine cover (gray) and locate a small gray knob that looks like a button on a shirt. While cranking the engine, crack that knob open and close a couple of times to bleed the air from the system. It will run like a champ then!