Kubota Fuel Problem

Total77

New member
Jan 13, 2011
1
0
0
Pottstown
We own a newer Kubota tractor L3130 with a 3cyl Diesel. I replaced a rubber fuel line and bled the system using the wheel/bleeder. The tractor seemed to be missing and was down on power, especially under load. I decided to further bleed the fuel lines individually off the pump by cracking the fitting loose and cranking the motor to make sure each cyl. was getting fuel and all are but now it produces thick black smoke. I called a dealer and they said underneath the fitting I cracked open there are FUEL DELIVERY VALVES and its possible the valve turned when i loosed the fuel line. I attempted to adjust the valves by turning them but by only 1 click in either direction its low on power and missing with no smoke, or runs smoother but with huge clouds of black smoke as it may be getting too much fuel. Im stumped. Any help is greatly appreciated. Thanks guys - Steve
 

Bulldog

Well-known member

Equipment
M 9000 DTC, L 3000 DT
Mar 30, 2010
5,440
73
48
Rocky Face, Georgia
I see you replaced a fuel line. Was the tractor running good before the line was replaced? Have the filters been changed? Can the line you replaced be sucking air?
 

sheradsch92

New member

Equipment
kubota L3800
Apr 17, 2017
3
0
0
Adair, OK
hello, so I have this same problem. On a L3800. I too have slipped the fuel delivery valves and machine still misses with no power. Could I hear any solutions? Filter bowl was knocked off and in replacement tractor would never prime properly.
 

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
hello, so I have this same problem. On a L3800. I too have slipped the fuel delivery valves and machine still misses with no power. Could I hear any solutions? Filter bowl was knocked off and in replacement tractor would never prime properly.
What do you mean "you slipped the delivery valves"?
Have you bled the lines at the injectors?
 

sheradsch92

New member

Equipment
kubota L3800
Apr 17, 2017
3
0
0
Adair, OK
As Total77 stated, I noticed in trying to loosen the injector lines from on top of the pump, the delivery valves slipped a notch past the keeper. This makes it get more fuel, engine races but still misses. I've adjusted the valves back to a point the engine does not race. Some where there still is a problem as engine still misses but I have fuel to all 3 injectors. Could it be I have an air leak? Or since this all started after fuel bowl got hit by a stick and broke, that contamination sucked past the broken filter and is sticking the injection pump?
 

sheradsch92

New member

Equipment
kubota L3800
Apr 17, 2017
3
0
0
Adair, OK
In trying to loosen injection lines, the fuel delivery valves slipped a notch past their timing preset lock. Causing engine to race and no governor. Then I removed locks and turned valve back a bit to stop the engine from racing. That worked but I'm sure they're not the flows they should be calibrated at. Also, bleeding injector lines and engine still misses. I'm wandering if when the fuel filter bowl got hit by a branch, if it dropped filter enough that some sediment or trash got into injection pump causing it to miss even after bleeding air?
 
Last edited:

eserv

Well-known member

Equipment
BX24, A1000 Kubota Generator
May 27, 2009
2,110
112
63
Hardisty, Alberta
In trying to loosen injection lines, the fuel delivery valves slipped a notch past their timing preset lock. Causing engine to race and no governor. Then I removed locks and turned valve back a bit to stop the engine from racing. That worked but I'm sure they're not the flows they should be calibrated at. Also, bleeding injector lines and engine still misses. I'm wandering if when the fuel filter bowl got hit by a branch, if it dropped filter enough that some sediment or trash got into injection pump causing it to miss even after bleeding air?
Those delivery valves should be tight. that clamp is not to hold some setting it is there to try and prevent you from loosening them when you remove the injector lines. this is a common occurrence and I'm sure lots of pumps get repaired for hundreds of dollars when all you need to do is tighten the buggers up.