I'm having a hard time from your post telling whether your tractor engine is not turning over or if it is, and not starting.
If it's turning over and not starting, does it have fuel to the injector pump? Start at the tank to fuel filter connection and make sur eyou have fuel flow. itshould be staedy and full flow. If it dribbles or is intermittent, then check the vent (usually in the cap) and if that's clear then drain the tank and check for a clogged fuel strainer at the tank outlet. if you have good fuel flow from the tank, check the filter head for clogging on the inlet side.R remove the line at the fltier head that goes to the injector pump and see if you have full flow through the filter. If you don't then replace the filter. (How long has it been since you changed the fuel filter?) If you have full outlet flow at the filter,bleed the pump and the injectors and try to start.
What are your ambient tempertures when you try to start. You're in OK so it's probably not teribly cold so it may not be glow plugs but some indirect injection diesels won't start without glow plugs so make sure that part of the starting assist is working. Can't help you there because i'm not familiar with those types of ngines systems.