Hi, I hope this is the right forum to get an answer to a baffling situation with my 4400 compact tractor, ser. no. above. 3 times in the last month I have shut it down after running for days with no problems and then the next morning it refuses to start. It cranks over fine but wont fire. I have the manual, read about the two coil fuel solenoid valve and how to trouble shoot the system. I have new oil, air, fuel filters, and all fuses and modules in the panel are o.k. I have felt the solenoid valve at the injector pump click in and out so thought the thermistor must be the problem. From a previous post here it indicated the thermistor was behind the fuse panel. The manual is very vague about the actual location. The electrical diaghram shows it to be at the K3 module, wires 85 and 87. Is it really behind the panel or is it contained within the K3 module which is about a 1" cubicle? The only consistency in failing to start is: shut down at night in the shed after a couple days of several starts, fail to crank within a 12 hr. overnight period, try multiple times over 3 days to start with no luck and then for whatever reason it decides to fire up instantly after say, 50 attempts. I would appreciate any experiences, guesses, or thoughts as to this problem and where that thermistor is located. Thanks very much. Steve in Florida