Fuel issue

331

New member
Sep 16, 2018
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Myrtle Beach SC US
Little help,

I have a 331 excavator with a Kubota engine. The machine started to sputter out like it wasn’t getting fuel. I went through and changed the pick up line in the fuel tank. The filter was in the tank but I placed an in line filter I could see. Changed the fuel filter. The primer bulb will get stiff after a few pumps but when I run the machine it stutters and the motor is shaking a little. When I squeeze the primer I can use the machine without problems.
Does this sound like a fuel pick up pump issue?
 

North Idaho Wolfman

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Jun 9, 2013
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It could be a lift pump issue or a filter issue.

Filter in the tank????
There is a screen on the pick up but that is not the filter, there is a filter after the primer bulb.

Look on page PM-14

http://vejledning.materielsektionen.dk/skabelon/pdf/1796.pdf

Doesn't sound like it's getting air in the fuel it sounds like it's just not getting fuel.
 
Last edited:

mickeyd

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Welcome to the OTT forum 331.

How did you make out with Florence? Anything except rain?
 

331

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Sep 16, 2018
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Myrtle Beach SC US
Flooding now. Not a lot of other damage but NC got it hard on the coast.

I changed all filters but when I sit there and squeeze the primer bulb it runs fine that why I think is a fuel pump issue.
 

thepumpguysc

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Aug 8, 2018
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Sunny South Carolina
Just pull the line off the tank & turn the key on.. Hold a can under it of course & watch the flow..
A faulty/clogged fuel cap will keep one from running too.. & u know all about mud daubers.. Loosen the fuel cap when it starts to chug.. or just leave it loose & run it.. see what happens.
DONT FORGET.. the fuel we're gonna be getting IS FULL OF WATER because of the flooding.. the underground tanks are filled w/ water..
Its a GOOD TIME to invest in one of those funnels w/ a filter..!!!
 

Blondie70

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Aug 6, 2016
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How did you get into the fuel tank ? Does it have a hatch on it where the fuel line goes in under the floorboard ?
Thanks, Pete
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
Just pull the line off the tank & turn the key on.. Hold a can under it of course & watch the flow..
A faulty/clogged fuel cap will keep one from running too.. & u know all about mud daubers.. Loosen the fuel cap when it starts to chug.. or just leave it loose & run it.. see what happens.
DONT FORGET.. the fuel we're gonna be getting IS FULL OF WATER because of the flooding.. the underground tanks are filled w/ water..
Its a GOOD TIME to invest in one of those funnels w/ a filter..!!!
That would work if it had an electric lift pump, but it does not, it's a mechanical lift pump that only move fuel when the motor is turning.

He needs to check it with the line off and cranking. ;)
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,285
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Sandpoint, ID
The fuel tank is under the foot mat and the pick up line is to the right of it.
Just trying figure out how to test the fuel pump?
Pull the line off before the jet start valve on the side of the injection pump, feed fuel to the injection pump from a bottle above it, then when you start the engine fuel will pulse out of the feed line, if it doesn't then you have a bad fuel pump (lift pump).

If you don't bottle feed the injection pump when you remove the line and crank it, you will suck air into the system and will need to bleed it at the injectors to get it to start and run. ;)
 

rentthis

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I have had a number of KX-71 and KX-91 Kubota excavators. On several of them, the fuel separators have gone bad and caused what you describe. The metal fittings where the fuel lines attach come loose and leak air. Your machine may have the same separator. You can plumb the separator out of the system long enough to see if it goes back to work. I have had to replace several.