M105S won't stay running

[bigdaddy070873]

I have a Kubota M105S that has a problem. It will start up then immediatley shut off. I replaced the fuel shut off selenoid 2 weeks ago and it was fine untill yesterday. It started by shutting off when brought off of an idle, then would only make a clicking noise(@ selenoid) kinda like a starter does when battery is dead. It then would start but then shut down. I can hear the selenoid click when I turn the key on and as soon as it starts i feel the selenoid click again. After it dies, i turn the key off then back on and the selenoid don't click. Does the selenoid have a relay that controls it? Or what else might it be? I am lost with this one and can't afford to take it to the dealer. Please help, I got tons of chemicals to spray!!!!

 

[CharlieS]

Though not likely, the replacement solenoid may be bad, but it sounds more like an intermittent power problem. When the tractor dies after starting, leave the key in the on position and test voltage at the fuel pump and see if you still have power at that point. If not you've got a loose connection somewhere, or possibly an ignition switch going bad. If power reads normal, then quite possibly its a bad ground.
Another simple test is make up a jumper wire to go from battery to pump solenoid and hook power to it directly from the battery, if the tractor starts and runs fine then you know solenoid and grounding is ok, so the problem would be in the switch or wiring from the switch.

 

[dirt clod]

If your in a bind and needing now could you disconnect the electric fuel shut off and just use the manual fuel shut off? I have a old kubota that the electric shut off didn't work when i bought it. Also have a old backhoe that does not have a electric shut off.

 

[Soundguy]

It does sound like power.. I think I'd bypass the ignition switch and see what I got. I know key-off diesels are nice.. but I prefer pull-to-stop better

soundguy

 

[bigdaddy070873]

I took off the selenoid(left it plugged in) and blocked the hole and it fired up and ran normal. I grounded the selenoid after I had it off and tried to start it just to see what it did and the selenoid just kicked in and out really fast(making the grinding noise I spoke of earlier)but it ran fine and didn't die. Swapped the relays and it still does the same thing. I wouldn't mind leaving it bypassed but seeing as how I use it to spray chemicals(very costly),if something happens, I need to shut down quickly.

 

[Soundguy]

check the wire that runs to the solenoid.. might be frayed or loose connections if the solenoid is chattering...

soundguy

 

[bigdaddy070873]

I traced them back into the main harness and they looked fine. There is a small nick in the wire near the plug but I don't think that it is big enough to matter. I may go ahead and replece it just incase.

 

[Soundguy]

bypass the wire, see if it helps. I've seen mor ethan one wire broke inside the insulation.

soundguy

 

[bigdaddy070873]

I'll give that a shot. Will let you know what happens. Thanks for all your help!!

 

[E/S]

One thing I would check first is the solenoid ground.
E/S