l2800 starts & shuts off

Herb in orange

New member

Equipment
l2800
Jan 1, 2022
6
2
3
orange, tx.
i tested all my switches and fuse box. the pto switches work but there is only power to one side. tried to jump it and blew a fuse. the power to the shut off lights up a test lamp and then shuts off. help it started with a double click when the ignition was turned on; but would still start if i advanced the rpms. this lasted a couple of days. then i turned it off in the field and it would not stay running. i removed the shut off control and taped the opening to get it back to the house. i observed that the fuel shut off would open and then shut off. i tested the wire feed and found that the current was doing the same thing. when i turned the key the first click would light up the test lamp followed by a second click which shut off the current. i believe the current should be constant at 12 volts on both pins. with regard to the switches, i do not know if there should be power to both sides of the pto. i tried testing it with the seat switch and the clutch depressed, no change. when testing the seat switch, i found that the switch connected the first pin to the third but i could not get power to the center pin. i don't mind fixing things but i hate mysteries. thanks for any help you can give me
 
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Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex.
May 24, 2019
3,876
1,528
113
North of Pittsburgh PA
Suggest you add more specific information.

For example, are you standing on the ground or in the seat when this happens?

Sounds like your safety interlock circuit is working, otherwise the starter would not turn the engine over.

Give as many details as you can, and someone that knows your tractor will likely give you some good help.
 

OrangeKrush

Well-known member

Equipment
BX2680, LA344 with Piranha tooth bar, LP PF 1242, LP Rear Blade, KK 60" BB
Nov 15, 2020
960
451
63
Indy
Starts and shuts off sounds like fuel starvation.. ?
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
4,683
664
113
Williamstown Ontario Canada
my first time on the site and i replied by editing the original post. i'll do better nest time.
There appear to be two possible transmission with a L2800. Manual or HST and each has their own wiring diagram.

The free WSM for your tractor on Kubotabooks.com should be avoided. It has scottish heritage and the safety systems are totally different than North American tractors.

I will provide the schematic for the OPC system. OPC stands for Operator Presence Controller.

Note in this schematic that there are two internal coils within the engine stop solenoid. This is important for you because of how your tractor is acting. One of these internal coils is strong and only operates for a short time to avoid overheating. It is called the PULL IN coil. It moves the solenoid plunger.

Once the plunger has been moved, the second coil takes over and keeps the plunger retracted so the engine continues to have a fuel supply. This second coil is weak but can operate continuously without over heating. It is called the HOLD coil.

I have not studied your symptoms like Henro has and my comments need to be reviewed. Follow Henro's lead and just use my comments to help you understand the system.

If the circuit for the pull in coil is operating the engine will start but as soon as you release the key switch from start the engine stops if the HOLD coil is not working.

forum L2800 OPC.jpg


The OPC timer mentioned above keeps the system, i.e. engine running for about 1 second. I think it is used to avoid brief triggering of the engine stop system when transitory events like wiggling in the seat are happening.

Dave
 

Herb in orange

New member

Equipment
l2800
Jan 1, 2022
6
2
3
orange, tx.
thanks for you reply. it appears i need a new stop solenoid. i tested it on the bench and neither pin would hold it open. however it would seem that the voltage feed would be constant on one of the two feeds to the stop solenoid. they both come on then shut off.
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
4,683
664
113
Williamstown Ontario Canada
thanks for you reply. it appears i need a new stop solenoid. i tested it on the bench and neither pin would hold it open. however it would seem that the voltage feed would be constant on one of the two feeds to the stop solenoid. they both come on then shut off.
If you are seeing irregularities in the power signal to the solenoid and with the solenoid itself, that would be most unusual,
How are you bench testing it?
With the solenoid body as a ground connection?

Can you take a OHM reading between each pin on the solenoid to the solenoid body.

Dave
 

Herb in orange

New member

Equipment
l2800
Jan 1, 2022
6
2
3
orange, tx.
i unplugged the solenoid and used a grounded test light touched to the pins going to the stop solenoid. both pins lite up the light for a second and then went dead. when this problem first started the solenoid would have a loud click followed by a second click which shut off the tractor. i was able to still start the tractor by advancing the throttle till this last time.
 

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex.
May 24, 2019
3,876
1,528
113
North of Pittsburgh PA
i unplugged the solenoid and used a grounded test light touched to the pins going to the stop solenoid. both pins lite up the light for a second and then went dead. when this problem first started the solenoid would have a loud click followed by a second click which shut off the tractor. i was able to still start the tractor by advancing the throttle till this last time.
I had trouble rereading your original post to see what you might have changed in that post.

However, it sounds like your using the grounded test light to verify what is going on as far as voltage supplied to the fuel cut off solenoid is a valid test, and indicates the problem is not with the fuel cutoff solenoid and is in the circuitry supplying voltage to the fuel cutoff solenoid.

Please keep us updated on further measurements you may make.
 

Herb in orange

New member

Equipment
l2800
Jan 1, 2022
6
2
3
orange, tx.
problem solved. it was the opc timer td060-305 which sell for around $100.00 it's located behind the instrument panel on the fire wall. thank everyone for their input and help. i learned a lot. herb in orange
 
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Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
4,683
664
113
Williamstown Ontario Canada
problem solved. it was the opc timer td060-305 which sell for around $100.00 it's located behind the instrument panel on the fire wall. thank everyone for their input and help. i learned a lot. herb in orange
A big favor I am asking............

Could you repeat your tests on the solenoid itself. When you reported both odd solenoid actions and also supply power issues, I became very confused and it would help any of my advice given in future if it were possible that your test of the solenoid was in some way flawed and in fact the solenoid was operating properly.
Dave
 

Herb in orange

New member

Equipment
l2800
Jan 1, 2022
6
2
3
orange, tx.
the stop solenoid would engage then shut off and was caused by the current doing the same thing. i tested the solenoid on the bench and found that one pin would not keep it engaged but if i crossed both pins it worked. the opc timer controls both wires and is suppose to keep one on when the key is on. i jumped the red to the black and the wire to the stop solenoid stayed on. i replaced the opc timer and it is working fine.
 
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