Only runs with key in start position

[bigDOJ]

Was running good, then started dying often, and now will only run when the key is in start position. Any Ideas??

 

[ruffdog]

Weak "hold" position on fuel solenoid?

 

[CausticUrbanCoast]

Check your grounding.

 

[the old grind]

If the starter turns over and the engine fires the fuel solenoid is as grounded as can be.

I suggest there's a faulty ignition switch from wear or corrosion.

btw, starter solenoids have pull and hold coils but few other do. The fuel solenoid is so much smaller and requires far less current to hold it. It likely doesn't use a relay either.

The fuel solenoid may be more like a diverter valve solenoid that draws a few amps vs a starter that takes nearly all a battery has.

 

[CausticUrbanCoast]

If the starter turns over and the engine fires the fuel solenoid is as grounded as can be.

I suggest there's a faulty ignition switch from wear or corrosion.

btw, starter solenoids have pull and hold coils but few other do. The fuel solenoid is so much smaller and requires far less current to hold it. It likely doesn't use a relay either.

The fuel solenoid may be more like a diverter valve solenoid that draws a few amps vs a starter that takes nearly all a battery has.

That is not always correct, the starter uses a different ground path than the rest of the system.

 

[the old grind]

The starter and fuel solenoid are grounded through the engine block. If they both work in the key start position they are grounded ok. Neither has a ground wire/connection to fail except the main ground to the engine. (wouldn't crank over)

A bad key switch might not send power to the solenoid in the run position I've replaced two ign switches and problems ceased. One was in '98 and one was in a '04. Both had spent plenty of time parked outdoors, but I suspect contact wear due to age & hours.

 

[ruffdog]

A key switch is easy to test for power sent to the fuel solenoid.

 

[bigDOJ]

The starter and fuel solenoid are grounded through the engine block. If they both work in the key start position they are grounded ok. Neither has a ground wire/connection to fail except the main ground to the engine. (wouldn't crank over)

A bad key switch might not send power to the solenoid in the run position I've replaced two ign switches and problems ceased. One was in '98 and one was in a '04. Both had spent plenty of time parked outdoors, but I suspect contact wear due to age & hours.

My original thought was a faulty key switch, that I replaced, after determining that it was not a fuel problem. The new switch did not solve the problem. Do you think it could be a bad solenoid or something else?? I am not very educated on these mechanical issues, so all of your help (in laymen's terms) is deeply appreciated. Thank you very much

 

[ruffdog]

Another thread and sounds similar:

Mitsubishi MT18D solenoid problem

 

[PILOON]

I had a similar problem on a borrowed B21.
Naturally I was far from my shop.
Could start and move as long as I left key in start.
OK, did that enough to clear the road and did trouble shooting.
After poking around I discovered a blown 40 amp fuse.
Naturally no spares so I pried it open and forced the fusable wire to make contact.
WORKED so I limped home., bought and installed new fuse.

Why is it troubles always show up when far away and no tools.

 

[CausticUrbanCoast]

Has it been verified that he even has a fuel shutoff solenoid?

 

[bigDOJ]

The plunger on the fuel solenoid stays open all the time, even when the key is in off position. After I start engine, it closes. If I unhook one of the wires connected to that solenoid, the tractor will stay running all the time. I have to put the key in start position again, before it will die. Does that mean I need a new fuel solenoid???? Or can I bypass the solenoid somehow? or is it OK to run the tractor like that?

 

[K5lwq]

Sounds like a relay issue to me.

 

[the old grind]

If the key is on and the gauges work I suggest running with the one wire disconnected if it will. It could lead to a stuck relay. I'd connect it & check it for ground or voltage with the engine off and the key in each position. Having a schematic could aid in diagnosing with a quick look but I suspect the wiring layout isn't too complicated.