# F935 fuel shut off silinoid



## Seve's (Sep 10, 2017)

new member although I have used you posts many times to solve problems. Seems like can't find the exact issues this time. 

I bought an f935 couple months ago. Three cylinder yanmar. Really liked it but about week ago started shutting down after about half hour of mowing. Would cool down then could go again. Couldn't find exact problem. Thought fuel shut off silinoid but seems to be working fine. Now it wouldn't start but noticed the silinoid wouldn't engage and let fuel thru unless the red ebrake pedal was pressed. Started fine but silinoid disengages as soon as pedal is released shutting off fuel. Found a switch under pedal and put in jumper so machine will stay running without pedal pressed but kills as soon as you try and go faster than barely moving speed say nothing about engaging pto. 

Has anyone had similar problems or things to check? Couple fun facts that are probably unrelated but will mention anyway. Non of my indicator lights work(battery oil pressure glow plugs pto engaged) haven't had time to dig into it thought bulbs may just be burned out but not the case. Also noticed previous owner put in a jumper accross the pto engaged bulb. Not sure what that would accomplish. Also the three fuses behind the seat there are two 25s and one 10 two were fried but when I replaced them the 10 instantly burned up again. Haven't spent allot of time following those wires. Any help and advice would be great. Thanks in advance.


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## RC Wells (Dec 26, 2008)

Read this thread regarding your electrical solenoid control issues: https://www.tractorforum.com/threads/john-deere-f935-question.10959/

Engine power loss under load or low speed is usually fuel related. Check condition of the fuel filter, and the screen on the end of the draw straw in the fuel tank. 

If yours has the solenoid on the backside of the injection pump, they fill with oil over time and require replacement. Easy to check, remove then compress the arm on the slug, if oil squirts out it is oil logged and will not fully open.


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## Seve's (Sep 10, 2017)

It's definitely something controlling the fuel shut off silinoid. Something is telling it to shut down when it shouldn't. I will take a look at those relays. electrical gremlins are definitely my weakness when it comes to working on this stuff. Had no idea how much electrical was in this thing

Thanks


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## Missouriboot (Jun 23, 2021)

Seve's said:


> new member although I have used you posts many times to solve problems. Seems like can't find the exact issues this time.
> 
> I bought an f935 couple months ago. Three cylinder yanmar. Really liked it but about week ago started shutting down after about half hour of mowing. Would cool down then could go again. Couldn't find exact problem. Thought fuel shut off silinoid but seems to be working fine. Now it wouldn't start but noticed the silinoid wouldn't engage and let fuel thru unless the red ebrake pedal was pressed. Started fine but silinoid disengages as soon as pedal is released shutting off fuel. Found a switch under pedal and put in jumper so machine will stay running without pedal pressed but kills as soon as you try and go faster than barely moving speed say nothing about engaging pto.
> 
> Has anyone had similar problems or things to check? Couple fun facts that are probably unrelated but will mention anyway. Non of my indicator lights work(battery oil pressure glow plugs pto engaged) haven't had time to dig into it thought bulbs may just be burned out but not the case. Also noticed previous owner put in a jumper accross the pto engaged bulb. Not sure what that would accomplish. Also the three fuses behind the seat there are two 25s and one 10 two were fried but when I replaced them the 10 instantly burned up again. Haven't spent allot of time following those wires. Any help and advice would be great. Thanks in advance.


Having a similar problem with my F935 JD . Same engine as you and my brother modified the starter switch so that you have to turn the switch to on but then pull a button to start the motor . The engine sounds great when running but as soon as I attempt to go forward or backwards the fuel solenoid shuts the power off it also shut the power off when I try to engage the PTO. I am afraid that his modifications have circumvented some safety switches Or circumvented the necessary sequence of events in order to prevent proper function of the PTO . Any input would be very much appreciated as I am not the mechanically Skilled one in my family. my dad was a fixer but he is is deceased, and my brother is not available presently to undo his apparently incorrect fix.


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