John Deere 4720 tractor won't start

   / John Deere 4720 tractor won't start #1  

JAKAFUTZ

New member
Joined
Apr 27, 2018
Messages
10
Tractor
John Deere 4720
I have a JD 4720 that cranks over but won't start. The last time it ran was two months ago and started just fine at that time. I've done a ton of research on this forum but haven't been able to figure it out. Most common problems have pointed to the solenoid or the thermistor. I tested every relay and checked all of the fuses and they're all ok. When I turn the key I can hear both the relay and the solenoid click. Many have suggested the thermistor so I pulled out the fuse box and took apart the wiring harness but I don't see anything remotely close to a thermistor. Could it be located elsewhere? Any other suggestions? I'm not an overly technical or mechanical guy but can figure things out fairly well if given a little guidance. Thanks.
 
   / John Deere 4720 tractor won't start #2  
Is your PTO lever engaged?
 
   / John Deere 4720 tractor won't start
  • Thread Starter
#3  
Good thought but it is not.
 
   / John Deere 4720 tractor won't start #4  
Has it got a fuel solenoid on the injection pump? I don't know much about the newer Tractors.. Injection pump or heiu injection?
 
   / John Deere 4720 tractor won't start #5  
Fuel filter plugged? Worth checking.
 
   / John Deere 4720 tractor won't start #6  
Open the bleed screw on the filter housing while someone cranks it over. Make sure there is no air coming out.

dsb
 
   / John Deere 4720 tractor won't start
  • Thread Starter
#7  
I had a spare fuel filter so I put that in and bled the air out. Plenty of gas flow so the solenoid is working fine. I think the next step is to check the safety switch. I'm not sure what else it could be.
 
   / John Deere 4720 tractor won't start
  • Thread Starter
#8  
Checked the safety switch and that is in working order. Any other suggestions?
 
   / John Deere 4720 tractor won't start #9  
Sounds like you have covered a number of bases. Have you checked the air filter?
 
   / John Deere 4720 tractor won't start #10  
2.4L?? w/ integrated fuel system.. under the valve cover??
It sounds like the control rack is stuck??
REMOVE the shut off solenoid & reach in the hole & see if you can push/pull the rack..
There are videos online that will show you how it works..
Just google JD 2.4l fuel system..
 
 
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