L3902 fuel problems

DSGarcia

New member

Equipment
Kubota L3902
Feb 15, 2024
1
0
1
Texas
My L3902 is only one year old. Recently it started losing power (RPMs oscillating up and down) while driving then dieing. Dealer sold me fuel filter & water separator filter when I explained my problem. I changed them out and bled the fuel system a few different times but the tractor still will not start since changing the filters. The fuel in the water separator drops down to the bottom of the top section when I crank the engine. After I stop, it slowly refills after a couple of minutes. I suppose I can make sure the gasket is seated properly, but I first wonder what is happening to all that fuel. It is not leaking anywhere. Also, could the outlet from the tank to the fuel line have been clogged from the beginning and it that my first problem to solve.
 

mdhughes

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L3901DT
Dec 10, 2014
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Ste Geneveive county, MO
Check to see what kind of flow you get if you take the hose going to the water separator off. If it doesn't flow good, then there is something in the tank that is blocking the output port.

Make sure you have something that you can clamp the hose with to stop the flow.
 

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
The Fuel system is a loop what the system doesn't use for the motor is returned to the tank.

Note: DO NOT open or disconnect any of the high pressure fuel lines, Either hard or soft lines.

Remove the line that feeds the separator (red) you should get good flow.
If you don't get good flow you have something in the tank restricting flow.
If you get good flow, Re connect, remove the output line (blue) you should get good flow.
If you don't get good flow, pull the input fitting and check for obstruction.
If you get good flow move on to next picture.

1708050568810.png


Pull the bleeder (green) and turn the key to run, do not crank or start it.
You should get good flow.
If you don't get flow, the electric lift pump electrical feed or the pump itself has failed.
If you get good flow, replace bleeder and leave it cracked and leave the key in the on position for several min to bleed the system.

1708050688861.png
 
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Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
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“Gas” is the wrong word to use for “diesel fuel”

If there is no fuel coming out that is a problem that needs to be addressed.

I think you may have some sort of biological or trash problem in the tank. Can you remove the line out of the fuel tank and see if there is any fuel there? Can you drain the tank and put fresh fuel in it and treat it for biological contamination?
 

old and tired

Well-known member

Equipment
L2800 HST; 2005; R4
I pulled off the line going into the fuel filter and there is no gas coming out. How do I un-obstruct the tank?
Just going to offer constructive advice about forums in general... The more information you can give us, the better the chance we can help you. For starters, Your profile only lists "Kabota B series" Which Kubota model is it? Our replies depend a lot on the model, If it's a B3350 - you would have LOTS of problems we might be able to list!!!

Actually, asking your question attached to an old thread already limits the number of people that might have an answer for you... Don't worry about the 2 questions that you've already asked... START a new Thread/Post in "Service, Repair & Maintenance" forum, List your tractor model #, and a little about the issue... "fuel problems"...

If you don't want to do that... this problem has been covered a few times, you can read other solutions here online. BUT if you do have a B3350, you have plenty of reading to do!!!

Lastly, you most likely have Algae in the tank, you can add a diesel fuel biocide, you might have a leaf that can cover the outlet, Let us know does the engine run then cuts off? Right now, use compress air to blow back into the tank and see if you get flow... and how much? Trickle or pours out? good luck!!