BX25D Fuel Supply Problems - Won't Run Above An Idle

[jtcweb]

I have a BX25D that looses power and won't run above an idle. I believe the problem has been the electric lift pump, however replacing it several times only results in it working for a few hours and then I don't have fuel at the injector pump again. I've replaced all the filters and even when and bought the $160 pump from a Kubota dealer. After less than an hour the problem came up again. Generally, if I let the tractor sit it will work again for a few minutes but then it goes right back to complete loss of power, barely able to move itself.

I'm stumped at what else the problem could be. When I change the electric lift pump (I've put in 4 of the cheap ones from Amazon and 1 from Kubota) the fuel pours out of the hose. That leads me to believe that the supply from the tank isn't the problem.

Any help on solving this problem would be greatly appricated.

 

[imnukensc]

If you haven't eliminated the tank as your problem, and it sounds like you haven't, then maybe that is the problem. That's where I'd start next instead of replacing fuel pumps and filters again.

 

[jtcweb]

If you haven't eliminated the tank as your problem, and it sounds like you haven't, then maybe that is the problem. That's where I'd start next instead of replacing fuel pumps and filters again.

I don't have a clue how to check out the tank. What should I look for?

 

[Henro]

I don't have a clue how to check out the tank. What should I look for?

In addition to the tank, make sure your vent in the fuel cap is open. Next time you have the issue, loosed the fuel cap and see if it makes a difference.

 

[tinkerwitheverything]

I know you say fuel outlet from the tank runs good. Problem is that if you have something in the tank that moves around and blocks the hole on the outlet your going to starve for fuel. Only way I can think of is to take the tank off and try to turn it upside down and see if you can get anything to come out of the filler. one thing You can try is, remove the hose from before the filters and if you can let it run into a container and see if the tank will drain out or if it stops flowing after awhile. You might have to add a extension onto the hose in order to make it long enough to reach into what ever your using for a container.

 

[GreensvilleJay]

You've got 'something' kinda floating, in the tank, partially plugging the 'spigot' that feed fuel to the filters and pump.
BTDT, with my BX23S last year. In my case it was a small black 'donut' shaped sliver of plastic.
I took a leisurely approach to the repair. It was summer afterall....
day one ..remove tank, get and print the diagrams from kubota parts or messicks
day two clean the tank..took 3 'fill and drain waters' to get the 'sliver ' out...blow out water several times.
day 3.. reinstall tank..slow and steady wins the race...
I asked Kubota what they'd charge( afterwards of course)... on 3 hrs labour( $350+-)
It's not that hard, take pictures just in case though. Seat unit is HEAVY, hyd stop knob is tricky to remove( $7 for a new one). seat pan is awkward. It'd be NICE to have 2 extra hands to help ! Oh yeah pump out the fuel first ,there's NO shutoff at the tank !

when all done and 'up and running', goto $store and get a sink strainer(middle size,$2), trim to fit fuel neck or buy a 'cold brew coffee filter' (some say they fit, $20)

 

[DustyRusty]

Before you go to the trouble of removing the tank, remove the hose from the tank and crimp it shut with a needle nose vice grip that you install some padding on the ends so they don't damage the rubber hose. Get your tank that you buy your diesel in, and a long piece of rubber hose, and connect that to the filter under the tractor with the hose in the portable tank. Start the engine, and allow it to normalize until the engine is running smooth. Then push the idle up to 2500/3000 RPM and see how long it will run at that speed. Give it 10 or 15 minutes and if everything is still OK, then you know the problem is in the tank. If you still have the problem, then it is with the engine, and that means a trip to the dealer with the tractor.

 

[85Hokie]

The aux tank is the answer to the larger problem - once this test is performed as Rusty explains - you will either find the problem or be looking in another direction entirely.

 

[jtcweb]

In addition to the tank, make sure your vent in the fuel cap is open. Next time you have the issue, loosed the fuel cap and see if it makes a difference.

I've done this - no change

 

[jtcweb]

The aux tank is the answer to the larger problem - once this test is performed as Rusty explains - you will either find the problem or be looking in another direction entirely.

I'll give this a try - is it just 1/4" fuel line?

One thing no one has mentioned is could it be an electrical problem? I used to be a computer hardware tech and in electronics, it is common for things to stop working after heating up.

 

[DustyRusty]

I'll give this a try - is it just 1/4" fuel line?

One thing no one has mentioned is could it be an electrical problem? I used to be a computer hardware tech and in electronics, it is common for things to stop working after heating up.

I doubt that it is electrical, since it is a basic diesel engine, and the only thing that runs on the electricity is the diesel pump and the shutdown solenoid. Once the engine starts, there is virtually nothing that requires an electrical current to keep it running.

 

[85Hokie]

I'll give this a try - is it just 1/4" fuel line?

One thing no one has mentioned is could it be an electrical problem? I used to be a computer hardware tech and in electronics, it is common for things to stop working after heating up.

it is not 1/4" line - use 5/16" - 8mm line - these are ID dimensions.

As for electrical - I too doubt that to be the problem.

 

[RalphVa]

Siphon tank contents and look inside. On my original tractor, it started choking down. Brought it back home (out snow moving) at about idle. Siphoned tank and found some wax globs mostly plugging the tank outlet. Fished out with one of those 3 fingered tools with a push gizmo on end to open/shut the fingers.

Had bought my only off road and had a couple night down below 10 F. Wax came out of solution.

 

[DustyRusty]

This is why I never trust the pump to have a winter blend fuel that will not gel at lower temperatures. I always treat my fuel with Service Power year-round. I see this as inexpensive insurance that my fuel will never cause me problems.

 

[jtcweb]

So it looks like I have a tank problem. The tractor stalled out again and I pulled the fuel line at the injector pump and only a dribble came out. I hooked a hose up to the lift pump and stuck the other end in a 5-gallon can and the end at the injector pump had a much greater flow.

What are my options to "fix" this problem? It sure looks like it is hard to pull the tank.

 

[Henro]

While it is not a fix, you might try blowing compressed air back through the line from the tank, just to clear what ever blockage might be there.

This would probably be a temporary "fix" if it helped...but you could get lucky for a while...

Question: Did you run the engine with the lift pump pulling fuel from the 5 gallon can?

 

[jtcweb]

Question: Did you run the engine with the lift pump pulling fuel from the 5 gallon can?

Yes - that's how I know the problem is not from the lif pump forward. The 5-gallon can was sitting on the ground so the lift pump had to lift more than normal.

 

[Henro]

Yes - that's how I know the problem is not from the lif pump forward. The 5-gallon can was sitting on the ground so the lift pump had to lift more than normal.

That is good to know. Did you run the engine at high RPM for a while?

So it looks like the issue is between the lift pump input side and the tank...

Time to bite the bullet I suppose...

If you had one of those fiber optic scopes that might help...looking into the tank on the exit side to see if there is something in there.

At least the positive is that it is likely a fuel supply problem and nothing related to the engine.

Edit: Still, do not write off blowing some air into the fuel line back into the tank...

 

[07wingnut]

While this is no help at all with your present problem, when you do get it fixed it would be to your advantage to rig so kind of strainer in the filler neck of the fuel tank. You don't need a real fine mesh because you don't want to restrict fuel flow when tanking up. Any particles small enough to make it thru a decent sized mesh will be taken care of by the fuel filters. Here is mine, made up of some pvc pipe and tea strainer mesh.