Kubota drops to very low RPM....

[spabula]

Hi everyone, new guy here. I was refered to this forum by some people on another forum that I belong to...
Ok so here goes... I have a Kubota BX2350 that has 60 hrs on it. It keeps dropping to a low RPM constantly. To the point I can not even use the tractor. I have replaced the fuel pump, both inline filters and also the diesel. It does not matter if i am sitting still, moving, not using a PTO or using a PTO... it still does it. I really have no idea what else to do.
Here is a video i took of the tach as its running sitting in my driveway..
VIDEO

Thanks in advance for all the help. BTW this site looks great I will definately be around!!

 

[dodge man]

It could be alot of things. I'm assuming you checked the air filter and intake system to make sure it's clear. Mice can get in strange places. What fuel pump did you replace? There is the main injection pump, which is most likely big bucks to replace, and there is a lift pump. The lift pump is a small silver colored pump and is towards the back of the tractor, and looks alot like a fuel filter. If you turn the key but don't start the tractor, you should here it run.

You might want to try replacing the filters again, it seems like 9 out of 10 times these things are fuel related. You can actually get growth in the tank. I've also read where debris can get in the tank and plug up the outlet for the tank. Mine started doing what yours is and replacing the rear fuel filter fixed it. The best thing might be trying to lossen the fuel lines one at a time starting at the back of the tractor. When my rear fuel filter plugged up, I was getting low flow after the filter, but plenty before the filter. When I put the new filter in there was an obvious difference. Just take the line loose and you should get a pretty good gush of fuel by gravity.


These are just a couple of ideas to try, good luck.

 

[spabula]

I replaced the small inline pump that looks like a filter. It was a factory replacement.. was around $100. The filters I pulled out, I cut open.. they were clean as a whistle...

 

[spabula]

Where is this main pump you are talking about located??

 

[RPW]

Follow the steel lines from the cylinders back and where they stop is your injector pump. My 2cents is either injector pump or computer (if this model has one).

 

[dodge man]

There is no computer on a BX. The main injection pump is on the engine, I think the left rear of the engine as I recall, but I'm not sure without looking. I also cut open my fuel filter and it looked fine, but it was plugged up to some degree. In my opinion, one problem of the BX is the tiny little filters they put on them. Most tractors have a much bigger filter.

 

[Kubota 2350]

How old is this tractor?
With only 60 hrs it should be fairly new and under warranty.

You sure don't want to have to buy an injection pump.

 

[spabula]

it just came out of warranty in july. i got it brand new in 2006.

 

[roamrdb]

have you checked the flow from the tank? remove the fuel line after the little supply pump, turn the switch on and see what kind of volume you have. i would suspect some kind of restriction in the line or the tank. i have seen all kinds of stuff end up in fuel tanks, from a leaf to a piece of plastic. if something covers the pickup or port in the tank it will demonstrate the symptoms you describe. anything is possible, but the injection pump would be my last suspect, especially considering the low hours.

 

[Soundguy]

every time I see a diesel loose rpms like that, with no cloud of black smoke.. it's a fuel starvation issue.

soundguy