Kabeta l 3901 won't start . the ignition was screwed up when it was almost stolen. the key still worked somewhat for a while then it started to throw codes . i replaced the ignition switch and cleared all codes except 2. i removed the ecu for about 60 days and then re installed it happily to find out that all codes were gone. Now it goes through startup with no problem and turns over but still won't start . the fuel pump has no power to it but all fused are all good and clean' i jumped the fuel pump but still won't start. what am i missing?
Kabota L 3901 Help
- Thread starter G.R.D.
- Start date
Do you have good flow from the tank? Can you get fuel through the filter? Have you checked the fuel shutoff solenoid?
This suggestion is a shot in the dark but I think worth verifying that the ECU knows it is connected to the correct tractor.
Dave
i have no power to the fuel pump. nor the the fuel shut off solenoid . or what i think is the fuel shutoff. it seems that some kind of switch somewhere is not allowing power to the fuel system. if that makes any sense. i need a wiring diagram of fuel system. is there some kind of sensor that would cause this?
LOL, Thanks for the spell check! At this point i am so frustrated with this machine.
I followed the instructions exactly and I get back the letter [A] I know that the problem is most likely operator error . What does this mean?
It sure does. It's right on target. Now the challenge is to find that that something is, which is keeping power from the fuel system.'
Safety switch, most likely.
Jumping the fuel pump wouldn't work unless you also jump the shutoff solenoid.
Besides the letter A is there a number after. If you have an HST tractor you should see A-1.
If you see A-0 or A-2 your ECU thinks it is on a different model tractor than yours
Dave
I don't know your tractor, so I"m only going by the diagram that's been posted above. Anyone who is familiar with this vehicle please correct me if I've got something wrong.
Looking at the wiring diagram #3, it appears that the electromagnetic fuel pump (#17) is being powered by the engine relay, #15. I'd take a look at that relay to see if it has power to the relay AND that the ECU is providing ground to trigger that relay. It should have battery power (hot at all times) through the 45 amp fuse (#3) and through a 20 amp fuse. That 20 amp fuse might be an inline fuse, which would be easy to miss.
If the engine relay has power to two terminals, then check for the ECU to ground one of the other terminals when you are trying to start. If it doesn't, then the ECU is not happy for some reason. That might be a fault with the ECU, or it might be that it's looking for an input that isn't there, such as a safety switch or other sensor.
That relay also powers the supply pump (#16) and provides signal to the glow plug relay (ECU will provide ground as needed).
Also check for the ECU to provide signal (possibly ground) to the injectors. The injectors should have either a two-wire setup or a single wire.
On the two wire setup, one is hot all the time (when the key is on) and the ECU provides ground when it wants to fire the injector. I think this is your setup.
On the single wire setup, it will have one switched hot wire and the body is grounded. In this case, the ECU provides 12v when it wants to fire the injector.
Looking at the wiring diagram #3, it appears that the electromagnetic fuel pump (#17) is being powered by the engine relay, #15. I'd take a look at that relay to see if it has power to the relay AND that the ECU is providing ground to trigger that relay. It should have battery power (hot at all times) through the 45 amp fuse (#3) and through a 20 amp fuse. That 20 amp fuse might be an inline fuse, which would be easy to miss.
If the engine relay has power to two terminals, then check for the ECU to ground one of the other terminals when you are trying to start. If it doesn't, then the ECU is not happy for some reason. That might be a fault with the ECU, or it might be that it's looking for an input that isn't there, such as a safety switch or other sensor.
That relay also powers the supply pump (#16) and provides signal to the glow plug relay (ECU will provide ground as needed).
Also check for the ECU to provide signal (possibly ground) to the injectors. The injectors should have either a two-wire setup or a single wire.
On the two wire setup, one is hot all the time (when the key is on) and the ECU provides ground when it wants to fire the injector. I think this is your setup.
On the single wire setup, it will have one switched hot wire and the body is grounded. In this case, the ECU provides 12v when it wants to fire the injector.
ok I got that part right now It is showing A-1 I checked the relays and are all good . I'm still getting no power to the fuel pump
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Have you verified the required voltage is present at the relay contact pin? Perhaps a defective or high resistance contact inside the relay. Easy to test with a VOM or try to swap relays with another and see if your pump voltage appears.
Stop looking at voltage to the pump!
You need to verify two things:
You need to verify two things:
- Does the relay have voltage to it?
- Is the ECU is trying to trigger the relay?
So if I manually jumped the shutoff solenoid and the fuel pump should it start?