Kubota B7300 fuel problem

ChevyD30

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Kubota B7300
Nov 21, 2015
4
0
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North Carolina
Hey I just bought my first Kubota tractor it is a B7300 and it is not getting fuel to the injectors I took off the lines and cleaned them out I pulled the injectors and cleaned them as well it had a lot of nasty stuff in them. It still is not getting fuel to the injectors it could it be that I have a bad fuel pump or injector pump? Can I get a rebuild kit for it? or what should I do. I have done a lot of carburetor work.
 

D2Cat

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As Bulldog said, fuel at IP? I'd suggest starting to check fuel delivery problem by starting at the tank.

Be sure you have fuel in the tank, then is fuel coming out of the tank? Is it getting to the fuel filter? Bleed filter. Go to IP, is fuel at the line coming into the pump?

Divide the fuel system up into small sections and confirm fuel presence until there is none.... then you know where the problem is.

When you do get a flow of fuel to the injectors you'll need to loosen the nuts there to let air out.
 

lugbolt

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I'm assuming the lift pump has been tested. That's the little mechanical pump below the main injection pump. Should have good output. You'll know if it's dead. Symptoms of a dead lift pump are low/no flow and sometimes fuel in the crankcase.

If you get good fuel TO the main injection pump, you're going to be looking at the shutoff lever. If that's "open" all the way and still no fuel, the injection pump is probably stuck. It doesn't pump much. I don't remember exactly how much per stroke but it ain't much. Maybe one or two cc per stroke, if that.
 

ChevyD30

New member

Equipment
Kubota B7300
Nov 21, 2015
4
0
0
North Carolina
the lift pump has good flow but the injector pump still barley has any flow out of it and is not enough pressure to get to the injectors.
 

ChevyD30

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Equipment
Kubota B7300
Nov 21, 2015
4
0
0
North Carolina
hey so I the fuel problem is fixed it was that the injector pump it was jammed up but it still will not start a friend of my brother told me that if the blow by tube which looks like a PCV thing to me but he said that if it has junk around it that it has a loss of compression.
 

lugbolt

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ZG127S-54
Oct 15, 2015
5,214
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Mid, South, USA
hey so I the fuel problem is fixed it was that the injector pump it was jammed up but it still will not start a friend of my brother told me that if the blow by tube which looks like a PCV thing to me but he said that if it has junk around it that it has a loss of compression.

Mmmm...maybe. There is always SOME oil vapor that comes out of that tube. And of course dirt/dust will stick to it. But if there's a LOT of air/vapor that comes out when cranking/running the engine, yes, the engine has some blowby. Has it ever been overheated? B7300, IIRC, did not have a temp gage, at least the earlier ones didn't. Just a light, and it was hard to see. Seen more than a couple that were so severely overheated that it took out the #2 cylinder and usually first complaint is "oil leak"...in other words, vapor and oil droplets coming out of the PCV tube.
 

North Idaho Wolfman

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Does it smoke at all when cranking?
Either out of the exhaust or out of the breather tube?
If it does what color is it?

Did you crack the injection lines at each injector and bleed the air out of each while cranking it?