L3301 Crank but no start

scottj93

New member

Equipment
Kubota L3301
Nov 9, 2024
2
1
3
Ontario canada
Hey new to the form and had my tractor for about a year (bought used) and haven't had any issues up till now. Now I turn the key on to accessory position all gages cycle and glow plug light comes on for about 1 second. Also the electric fuel pump has no power going to it. I have disconnected the pump and checked at the connector 0 volts at connector. If I put 12v direct the pump runs. I have checked all the fuses none are blown. Checked relays at the battery all good there aswell. Any suggestions on the next step or any one have this issue and know the fix. Any information would be appreciated
 

RCW

Well-known member
Lifetime Member

Equipment
BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
9,088
5,100
113
Chenango County, NY
Not familiar with your tractor but lack of power to the lift pump sounds like it could be a safety switch.

Make sure the PTO lever is off and the HST pedal is centered.

Try Kubotabooks.com for a workshop manual (WSM).

EDIT - I overlooked that it cranks. Usually a safety switch problem will not allow it to crank. Sorry about the diversion.

A WSM would be valuable though.
 

scottj93

New member

Equipment
Kubota L3301
Nov 9, 2024
2
1
3
Ontario canada
Not familiar with your tractor but lack of power to the lift pump sounds like it could be a safety switch.

Make sure the PTO lever is off and the HST pedal is centered.

Try Kubotabooks.com for a workshop manual (WSM).

EDIT - I overlooked that it cranks. Usually a safety switch problem will not allow it to crank. Sorry about the diversion.

A WSM would be valuable though.
No worries. I was just about to say would not crank over if was safety switch. I have been reviewing the wsm and haven't had any luck. But thank you for the input!
 
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lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,199
1,885
113
Mid, South, USA
fuel pump runs off of the ECU. So, you have to figure out why the ECU is not grounding the pump. Could be a lot of things.
 
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Mark_BX25D

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Equipment
Bx25D
Jul 19, 2020
1,735
1,246
113
Virginia
fuel pump runs off of the ECU. So, you have to figure out why the ECU is not grounding the pump.
ECU provides both power and ground to the fuel pump according to that diagram. He's got ground, but he's not getting 12v.

Well, wait a minute. Scott, you say you check at the connector and it's 0v. IS that checking with the meter grounded somewhere else? Or are you putting the meter probes on both of the contacts of the connector?

Try it both ways and report back. Here's where I'm going with this - the ECU might be providing ground, but no 12v, OR the other way around. OR maybe it's not doing either one. That's three possibilities.

If you measure voltage across the connector contacts, it will read the same 0v each of the three possible ways. BUT if you put your black probe on a good chassis ground, and you sill measure 0v, then the ECU not providing 12v.

If you put your red probe on a 12v source, and your black lead on the ground contact, and still measure 0v, then it's not providing a ground path.

Try that, please, and report back.

But those tests aside, let's look at a high level for a moment.

Something is making the ECU not happy. Either it's broken, or it's not seeing the inputs it wants to see.

The good news is, ECUs are not female. If it's not broken internally (rare but possible), then once it gets all of the inputs it wants to see, it will fire. Try that woman and it's still a roll of the dice. :)

So take a look at the inputs, and figure out what they need to be in order to provide BOTH power and ground to the fuel pump. Probe the correct wire for each necessary input, and see if it's giving the right signal. The one that isn't, is your problem.

If ALL are giving the right signal, and you still don't get the correct output, then your ECU is fried.

That's the process, anyway, at a high level.

A notebook is your friend. There's no way you can troubleshoot this kind of thing by keeping everything in your noggin. Electronic or pen and paper, whatever works for you, but write down the results of EVERY test you do, and how you did the test.
 
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