Kubota BX24 Injector pump problem

[fred98050]

Hi,
I recently experienced some problem with my BX24. Engine shutdown and wouldn't start again.
Check fuel pump, filters etc... Fuel was coming to the injector pump but nothing out of it..
Removed the injector pump, for inspection, cleaned the banjo bolt and all injector lines. Re install injector pump and engine started.
It ran fine until today. Same thing happened. The engine just quit...

This time I have fuel squirting out of the injector pump, bled the injector line (fuel dripping) but still no start. Not even white or black some coming out of the exhaust. Looks like no fuel is getting in chamber.

Question:

Is it possible to have fuel squirting out of injector pump but not have enough pressure to start engine ?

I am at a complete loss here... I am wondering if the injector pump isn't too weak...

Any suggestions?

Thank you

Frederic

 

[leonz]

Hi,
I recently experienced some problem with my BX24. Engine shutdown and wouldn't start again.
Check fuel pump, filters etc... Fuel was coming to the injector pump but nothing out of it..
Removed the injector pump, for inspection, cleaned the banjo bolt and all injector lines. Re install injector pump and engine started.
It ran fine until today. Same thing happened. The engine just quit...

This time I have fuel squirting out of the injector pump, bled the injector line (fuel dripping) but still no start. Not even white or black some coming out of the exhaust. Looks like no fuel is getting in chamber.

Question:

Is it possible to have fuel squirting out of injector pump but not have enough pressure to start engine ?

I am at a complete loss here... I am wondering if the injector pump isn't too weak...

Any suggestions?

Thank you

Frederic

About your injection pump:

As long as the crankshaft is turning the injection pump will pump fuel into the indirect injection system and overflow back to tank.

It takes thousands of hours to do damage to an injection pump of any manufacture unless the seal is blown behind the driven gear of the injection pump.


Where specifically is the diesel fuel squirting out of the injection pump?


EDIT: did you open the bleeder on the injection pump to bleed the air out of the fuel lines and not at each injection nozzle(I hope).

It is entirely possible the copper compression washers need to be replaced on the injection pump as it may be air locked due to the crazy fuel pump delivery system and inexpensive rubber hosing used from the tank on these things.

 

[fred98050]

Leonz,

Thanks for the reply.

Sorry wasn't clear enough.
When I removed the 3 injector lines and cranked the engine I can see fuel squirting out of the 3 injector pump nozzles.

Few weeks ago I had the same problem (engine quit) and at the time I couldn't see any fuel squirting out of the pump nozzles. After cleaning up the banjo bolt at the pump fuel inlet it started just fine.

I talked to Kubota and what I was told was that any kind of fuel contamination (water, dirt etc..) can damage the injector pump. They apparently have very small operating tolerances.

I am just curious here. Is it possible to see fuel coming out of the injector pump nozzles and still have a defective pump?

Thanks

Frederic

 

[kuboman]

Leonz,

Thanks for the reply.

Sorry wasn't clear enough.
When I removed the 3 injector lines and cranked the engine I can see fuel squirting out of the 3 injector pump nozzles.

Few weeks ago I had the same problem (engine quit) and at the time I couldn't see any fuel squirting out of the pump nozzles. After cleaning up the banjo bolt at the pump fuel inlet it started just fine.

I talked to Kubota and what I was told was that any kind of fuel contamination (water, dirt etc..) can damage the injector pump. They apparently have very small operating tolerances.

I am just curious here. Is it possible to see fuel coming out of the injector pump nozzles and still have a defective pump?

Thanks

Frederic

Loosen the lines right at the injector and you should get fuel there. You can get airlocks in the injector lines themselves. If you get fuel at the injectors and white smoke but still no start you might have a glowplug problem or fuel contamination.

 

[fred98050]

Done all that, . No start and No smoke white or black...

 

[leonz]

Hello Fred,

AS usual I am rolling my eyes at their lame response A_)(*&^%$%^&*()S!!!!!

First I would replace the filters and clean the bowl if it has one
Second change all the fuel lines to the suction fitting on the injection pump where the hose slides on if your pump is set this way and then change the copper washers.

Puchase new washers for this banjo fitting first, bleed it only at the bleeder as it could be airlocked severely in the injection pump and then go do the rest if the problem is not corrected.

Use a bit of air pressure and a rag to cover the filler port to force the fuel through to the electric pump to get it to pump the fuel to the injection pump by turning the starter switch to the "on" position first and if its not clicking UGH!!!!-new pump!!, I "Hate" the design of these things as they make it much harder to maintain them.

The indirect fuel delivery system is easy to maintain and repair the problem is when people make it more difficult thinking YEA that will work using lousy tubing and electric pumps to compensate for a lower than engine tank designed prime mover.

as l;ong as you have fuel, a pressure gradient to move fuell and no air in the indirect pumping mechanism/ system to block the operation of an indirect injection system preventing overflow fuel to return to tank "ZERO" issues.


If you had a defective pump it would run poorly/barely run at all/as it could barely pump fuel if the internals/seals/springs were shot.

A Nippondezo indirect injection pump like a Duetz/Robert Bosch indirect injection pump is a precision piece of machinery. It takes thousands of hours of operation to kill one of these things IF the proper fuel filtration occurs.

Have you checked the crankcase for diesel fuel contamination?

Is the fuel treated/fresh?

Have you replaced both fuel filters and cleaned the fuel bowl if it has one?

You could have ice in the fuel lines or a collapsed fuel line due to the cheap rrubber hoses they use.



I would replace the copper washer(s) as most diesel banjo bolts have 2 of them prior to bleeding the injection pump at the Bleeder and not the fuel lines entering the nozzles as veyr little fuel is entering the cylinders while bleeding.


You have to unclamp and remove the steel lines to remove the injection nozzles from the cylinder heads. I believe you are referring the female swivel fittings on the end of each steel line that attach to the nozzle bodies I believe.


I always tell everyone to change the fuel fltration system on these things with a RACOR centrifuge fuel system and eliminate the two inline fuel filters
(and replace the cheap fuel line with the Racor reinforced fuel line to protect your engines) as it removes all the crap the first time and spins the water out of their fuel.


The other option is the RACOR fuel filter funnel which removes the dirt/crap/water down to 2 micron as well depending on which model funnel you buy cheap insurance at $40 or so bucks if you do not want to install a small centrifugal filter which spins the fuel clean down to 2 micron if desired and plugs the final filter if water is present to the point the engine stops dead.

 

[fred98050]

Hello Fred,

AS usual I am rolling my eyes at their lame response A_)(*&^%$%^&*()S!!!!!

First I would replace the filters and clean the bowl if it has one
Second change all the fuel lines to the suction fitting on the injection pump where the hose slides on if your pump is set this way and then change the copper washers.

Puchase new washers for this banjo fitting first, bleed it only at the bleeder as it could be airlocked severely in the injection pump and then go do the rest if the problem is not corrected.

Use a bit of air pressure and a rag to cover the filler port to force the fuel through to the electric pump to get it to pump the fuel to the injection pump by turning the starter switch to the "on" position first and if its not clicking UGH!!!!-new pump!!, I "Hate" the design of these things as they make it much harder to maintain them.

The indirect fuel delivery system is easy to maintain and repair the problem is when people make it more difficult thinking YEA that will work using lousy tubing and electric pumps to compensate for a lower than engine tank designed prime mover.

as l;ong as you have fuel, a pressure gradient to move fuell and no air in the indirect pumping mechanism/ system to block the operation of an indirect injection system preventing overflow fuel to return to tank "ZERO" issues.


If you had a defective pump it would run poorly/barely run at all/as it could barely pump fuel if the internals/seals/springs were shot.

A Nippondezo indirect injection pump like a Duetz/Robert Bosch indirect injection pump is a precision piece of machinery. It takes thousands of hours of operation to kill one of these things IF the proper fuel filtration occurs.

Have you checked the crankcase for diesel fuel contamination?

Is the fuel treated/fresh?

Have you replaced both fuel filters and cleaned the fuel bowl if it has one?

You could have ice in the fuel lines or a collapsed fuel line due to the cheap rrubber hoses they use.



I would replace the copper washer(s) as most diesel banjo bolts have 2 of them prior to bleeding the injection pump at the Bleeder and not the fuel lines entering the nozzles as veyr little fuel is entering the cylinders while bleeding.


You have to unclamp and remove the steel lines to remove the injection nozzles from the cylinder heads. I believe you are referring the female swivel fittings on the end of each steel line that attach to the nozzle bodies I believe.


I always tell everyone to change the fuel fltration system on these things with a RACOR centrifuge fuel system and eliminate the two inline fuel filters
(and replace the cheap fuel line with the Racor reinforced fuel line to protect your engines) as it removes all the crap the first time and spins the water out of their fuel.


The other option is the RACOR fuel filter funnel which removes the dirt/crap/water down to 2 micron as well depending on which model funnel you buy cheap insurance at $40 or so bucks if you do not want to install a small centrifugal filter which spins the fuel clean down to 2 micron if desired and plugs the final filter if water is present to the point the engine stops dead.

Leonz,

Thanks again for this very detailed reply.

I'll start working on it again tomorrow morning. I will follow all your suggestions step by step and report asap (i'll include photos and video if need be).

Thanks again I really appreciate your help.

Frederic

 

[yooper jim]

Leonz
I agree with your suggestions, but the Racor seems like overkill. It would be worth it if I had constant problems. Never have had any trouble. I change the two filters once a year w/Kubota in line filters. I wonder how many microns they are?

Racor 500FG Fuel Filter Water Separater $167
Fittings for 500FG $25
Racor Fuel Filter Funnel RAC-RFF8C $48.72
Racor CGH6 5/16" ID Size Hose $8.50 / ft

Now ..... if I were on a boat on the ocean you would have me convinced. A tractor ........... I'll walk home.
Jim

 

[radioman]

Did you replace both fuel filters? Its the common problem with the BX's to slow down the flow or shut off. Also did you observe the soleniod plunger shutoff? did you try to wiggle it out to see if it was in partially?

 

[kuboman]

Leonz
I agree with your suggestions, but the Racor seems like overkill. It would be worth it if I had constant problems. Never have had any trouble. I change the two filters once a year w/Kubota in line filters. I wonder how many microns they are?

Racor 500FG Fuel Filter Water Separater $167
Fittings for 500FG $25
Racor Fuel Filter Funnel RAC-RFF8C $48.72
Racor CGH6 5/16" ID Size Hose $8.50 / ft

Now ..... if I were on a boat on the ocean you would have me convinced. A tractor ........... I'll walk home.
Jim

Except the logistics of installing a Racor on these little tractors it is a good idea. The micron rating the Kubota filter is 30. Kinda coarse. The racors go down to 2 micron which maybe slight over kill but 10 is a minimum.