3320 Fuel Delivery Pump Failure

[tony_adrian]

Yesterday my 3320 was running smoothly as it has since it was new. Suddenly the engine started missing like it was running out of diesel and then stalled. The fuel tank was half full.

It appears the fuel pump to the injector pump has failed. Tomorrow I'm going to take the bottom off of the pump and see if either of the little piston or the little pin are seized.

Assuming the pump has failed and can't be repaired would it be possible to simply bypass the mechanical pump with an after-market electric fuel pump? These are considerably cheaper than the mechanical pumps.

Any advise is appreciated,

Tony

 

[treaney]

Could it be a fuel starvation problem caused by dirt in the supply line?

 

[tony_adrian]

I disconnected the supply line at the fuel pump and easily blew thru it and heard the bubbles in the fuel tank.

Tony

Could it be a fuel starvation problem caused by dirt in the supply line?

 

[ixer0]

Tony, If you didn't take the banjo bolt out of the inlet connection it would be worth checking as they often get blocked. In answer to your electric pump question, yes you can fit one but that is not normally necessary. Look for the obvious things first.

Good luck. Mike

 

[tony_adrian]

I removed the fuel delivery pump. It is held onto the bottom of the injector pump with two small nuts. Once the unit is removed from the injector pump you can see sticking out of the top of the fuel pump is a shiny metal pin that is driven by what appears to be a cam in the injector pump. In my case the pin was seized in its bushing. This pin drives the fuel delivery pump that is the bottom section.

After removing the seized pin I noted no scoring or signs of overheating. There is a little oil journal that appears to lubricate this pin. Using a 17mm wrench I removed the bushing with the pin. I lubricated everything well and drove the pin out with a brass drift. I got some valve lapping compound ($3.00 a tube) and smeared it all over the pin and the bushing. I secured the pin in an electric drill and used it to ream out the bushing. I went slow and every few seconds would clean everything and then test for fit after lubricating. After a while it was sliding smoothly but was not sloppy loose.

Cleaned and remounted the pump, bled the fuel lines at the injectors, and that baby is humming along like new as I type this message.

I wonder if that little oil journal might have been temporarily plugged causing the pint to overheat and expand.

I really do appreciate the elegant simplicity of this workhorse tractor.

Tony

 

[zetor3545]

have you remembered to refill your pump with oil

 

[mosby7]

Where do you refill the injector pump? Thanks

 

[diyfarmer]

I thought all the modern pumps are oiled from the engine.