B7300 "Starves" for fuel

[Steve102C3]

My B7300 recently started 'starving' for fuel. Air is being introduced to the fuel system somewhere.

When the engine begins sputtering I can watch the clear housing the fuel filter is in. I see that the fuel level goes to the bottom of the clear housing then the tractor acts like it's out of fuel, of course.

When the engine dies, gravity fills the fuel assembly up again. I can restart, much like when replacing the fuel filter.

I have replaced the filter assembly with a new one, which also includes a fuel filter. I didn't open the assembly because it came complete and the retainer ring was good and tight.

I have a few ideas about what to check but want some insight from others first.

Could it be one of the fuel lines:
*Fuel tank to filter assembly?
*Filter assembly to transfer pump?
*Transfer pump to injector pump?

Or could it be the transfer pump itself. I have another tractor where the transfer pump failed, but that seems to be a rare failure.

I have also removed the fuel tank to confirm there is no trash in the bottom that is blocking the fuel; I've had that happen on another tractor, but I'm confident the line from the tank to the filter assembly is good.

I don't have any fuel leaks so I'm doubtful that any of the other fuel lines are bad; especially the one from the transfer pump to the injector pump because that should see some pressure.

These thoughts bring me back to the transfer pump.

Does anyone have any insight on this issue?

Thanks in advance,

Steve

 

[dodge man]

When I had a Kubota you could hear the small lift pump clicking when you turned the key on but didn’t start it. Can you hear a clicking on yours?

 

[Steve102C3]

I've never heard a clicking on this one.

The transfer pump is driven off the camshaft.

 

[RjCorazza]

You could be sucking air anywhere from the lift pump back to the tank and not necessarily see a leak. I think I would be looking hard at the suction side fuel lines, particularly from the filter back to the tank.

 

[thepumpguysc]

Lift pump or clogged vent in the cap..
Next time u notice the level going down in the bowl, reach up and unscrew the tank cap and see it it comes back up..

 

[Steve102C3]

Lift pump or clogged vent in the cap..
Next time u notice the level going down in the bowl, reach up and unscrew the tank cap and see it it comes back up..

I thought of this once when I was mowing.

I took the fuel cap off; there was no change.

This makes me think it may be the transfer pump.

Steve

 

[270Drew]

My father-in-law had a B23xx and it would run good for a while then die. It took the dealer a couple of tries, but eventually they found a bumble bee in the tank that would block the suction line in the tank.

 

[rScotty]

You could be sucking air anywhere from the lift pump back to the tank and not necessarily see a leak. I think I would be looking hard at the suction side fuel lines, particularly from the filter back to the tank.

That's what I think, too. Suction air leak just as and where RJ says. Bubble is pulled in and then rises to the fuel filter where the bubble eventually displaces all the incoming fuel. Often no fuel leak shows in a suction leak. Good culprits are bad connection or old hose - especially if a hose clamp is used.
rScotty

 

[Steve102C3]

I will replace the 2 fuel lines before the transfer pump and see if that works.

I'll try to remember to post a follow up for future reference.

Steve

 

[Steve102C3]

UPDATE:

New fuel lines arrived this week.

First I replaced the easy one: from the filter to the transfer pump. This didn't fix the problem.

Then I replaced the fuel line from the tank to the filter. This required me to remove the cowl and lift the tank to access the fuel line. A simple 5 minute fuel line replacement requires only 45 minutes to remove everything and another 45 minutes +/- to put it all back together.

The good news is the 2nd line seems to have fixed the problem.

For now I will leave the transfer pump as is.