kubota Runaway

[oldddog53]

I have a 2011 Kubota D722 in a Club Car Mule.Recently the engine would not start. I discovered that I could tap the front of the fuel pump solenoid and the engine would run fine. After a week or so I started the unit like this (sometimes it would start normally) and the engine revs went full on and the engine refused to die when the key was turned to the off position for several seconds. I went down and bought the new solenoid and installed it in the pump. The engine started normally but again went full throttle and this time it refused to stop at all. I had to pull the fuel line at the filter and run it out of fuel to make it stop. I even unplugged the solenoid completely with no effect. Does anyone have an idea as to what is wrong. I'm out of ideas.

Oldddog53.

 

[mddorange]

:welcome:
To the forum OldDDog53. We are glad that you joined.

Where are you located? You didn't specify if you CC was gas or diesel.

Sounds like it may be wiring were there is a constant demand on the solenoid.

 

[oldddog53]

I have a 2011 Kubota D722 in a Club Car Mule.Recently the engine would not start. I discovered that I could tap the front of the fuel pump solenoid and the engine would run fine. After a week or so I started the unit like this (sometimes it would start normally) and the engine revs went full on and the engine refused to die when the key was turned to the off position for several seconds. I went down and bought the new solenoid and installed it in the pump. The engine started normally but again went full throttle and this time it refused to stop at all. I had to pull the fuel line at the filter and run it out of fuel to make it stop. I even unplugged the solenoid completely with no effect. Does anyone have an idea as to what is wrong. I'm out of ideas.

Oldddog53.

I'm sorry I guess I should have been more specific. I thought the D722 would designate that it was a diesel engine. But to your post the engine will start with the key now that I have changed the electric pump solenoid but it will not turn off at all even if you unplug the solenoid completely. Also the engine runs full open and will not slow down at all. While the solenoid is electric the accelerator is manual foot feed with a wire cable and it is in the idle position (not stuck open) so I am beginning to believe that I have an internal pump problem.

 

[CobyRupert]

But to your post the engine will start with the key now that I have changed the electric pump solenoid but it will not turn off at all even if you unplug the solenoid completely. Also the engine runs full open and will not slow down at all. While the solenoid is electric the accelerator is manual foot feed with a wire cable and it is in the idle position (not stuck open) so I am beginning to believe that I have an internal pump problem.

Seems like that would explain why it goes to full throttle, but I'm wondering why your solenoid doesn't cut the fuel?

(Note: a diesel "runaway" is sometimes when the engine starts using motor oil as its fuel (because of an oil leak, especially at turbos, etc..) and the only way to stop it is to block the air intake. Probably not your situation, you'd probably notice a lot of smoke, but keep this in mind if cutting the diesel fuel doesn't always stop it. )

 

[oldddog53]

Thank you I will

 

[coolreinfarm]

I might be way off base here but a friend of mine had a bx 2660 tractor and he called me that he couldn’t get it to shut off, but he also said that the battery was dead, so I told him to jump the battery to a good battery and try to shut it down and it worked, so that tells me that 12v is applied to the solenoid to close the fuel. I have a International 234 which is a Mitsubishi and it has a timer relay connected to the solenoid and it also applies 12v to shut the engine down then clicks after 5-6 seconds for a restart. Now I don’t know why it’s going full throttle, hopefully a linkage problem.

 

[Oldoak]

One think I really liked about my JD 2350 utility tractor was that it had a manual fuel shut-off as well as an electric solenoid fuel cut-off. I used the manual fuel cut-off once in a great while just to check that it worked properly, but the electric solenoid never failed me. I think that duel system should be standard on all diesel engines.

 

[Industrial Toys]

WEIRD! I have this engine in my Steiner. It has only two controls on the pump. The shutoff and throttle. My throttle is leaking oil out of the pump and I have a seal kit to fix that, but it has never given me any operational problems, just makes a mess.