Repair Kubota

[Hammermechanicman]

Do you mean a mechanical pump that feeds fuel to the injector pump? If so disconnect the line coming out and crank engine and see if fuel pulses out. If you can test fuel pressure check for around 5 to 7 psi out of the lift pump. Do you have any fuel in the crankcase oil? If so bad diaphragm in the lift pump.

 

[cambre]

Do you mean a mechanical pump that feeds fuel to the injector pump? If so disconnect the line coming out and crank engine and see if fuel pulses out. If you can test fuel pressure check for around 5 to 7 psi out of the lift pump. Do you have any fuel in the crankcase oil? If so bad diaphragm in the lift pump.

Yes, the fuel pump feeds the injector pump. I don't have anything to test fuel pressure. No fuel in crankcase oil. Thanks, I have a new filter bowl coming. Gonna try that. I'll let you know if it fixes problem.

 

[cambre]

I have made mistakes (this is nothing new) while trying to explain my problem. The engine has 2 filters. I put on a new fuel filter assembly (the large one) thinking the old one may have a pin hole in the plastic bowl. It has a mechanical fuel pump witch is pumping fuel. Changed small filter also. Still runs and dies. Next I changed all flexible fuel lines. Bled the system and it runs and dies. At my wits end. I did pull fuel line from fuel pump, it seems to pump plenty of fuel, at lease 5psi.

 

[cambre]

Almost all diesel motors have some sort of lift pump to supply fuel to the injector pump. The pump can be mechanical or electric. If the injection pump is sucking air and there are no leaks in the fuel line fuel is not being pushed to the injection pump.

The only thing I haven't done is pull the fuel line from the tank to see if any trash in it. Also the bleed bolt on the injector pump sprays plenty fuel,

 

[Hammermechanicman]

One of the things you can try is to check the fuel pickup in the tank then get a cheap 12v electric fuel pump and connect it directly from the tank to the injection pump. If it still won't run you may have an injector pump problem. If it runs good you know you have a problem between tank and injection pump.

 

[cpurvis]

Don't connect a line from the tank to the injection pump without a filter between the two. Injection pumps do not tolerate any dirt in the fuel.

 

[cambre]

Thanks, I will try that.

 

[cambre]

One of the things you can try is to check the fuel pickup in the tank then get a cheap 12v electric fuel pump and connect it directly from the tank to the injection pump. If it still won't run you may have an injector pump problem. If it runs good you know you have a problem between tank and injection pump.

I will try that.

 

[cambre]

Don't connect a line from the tank to the injection pump without a filter between the two. Injection pumps do not tolerate any dirt in the fuel.

So you mean to bypass the two original fuel filters and run a fuel line from the tank to injector pump with an electric fuel pump in the fuel line between tank and and injector pump. This reply is for Hammermechanicman also. I have a neighbor that told me he had same problem with a 25HP Kobota engine, He said he kept running it until it got rid of the air. He said it ran bad and gradually ran better and better. I started it today and started mowing thick grass. Putting a load on the engine, it has a little more than half the power before all this started. It ran for over 10 minutes and died. I let it sit for an hour and it started so I put it back in the shop. I will do the same thing in the morning. I am so glad I have you guys staying with me on this. Thanks.

 

[cpurvis]

So you mean to bypass the two original fuel filters and run a fuel line from the tank to injector pump with an electric fuel pump in the fuel line between tank and and injector pump. This reply is for Hammermechanicman also. I have a neighbor that told me he had same problem with a 25HP Kobota engine, He said he kept running it until it got rid of the air. He said it ran bad and gradually ran better and better. I started it today and started mowing thick grass. Putting a load on the engine, it has a little more than half the power before all this started. It ran for over 10 minutes and died. I let it sit for an hour and it started so I put it back in the shop. I will do the same thing in the morning. I am so glad I have you guys staying with me on this. Thanks.

If it has half the power that it used to have, that means it's getting half the fuel it used to get. Fuel flow restriction--or air--in the system will cause this.

I would start it and just let it run at about 1500 rpm and see if it shuts off again.