Tractor has been starting great all winter in sub freezing temps. Pulled it outside to thaw snow from bucket for the day. Started and put tractor to bed. Next day tractor cranks but will not start. Checked glow plugs good. Next thought water in fuel. Put a little treatment in tank and changed out both fuel filters. Cleaned/blew out fuel lines and injector lines. Opened bleeder screw on injection pump have good fuel flow. Inline fuel pump is good. Still no start. Remove fuel stop solenoid to check operation pulls in when cranking like it should. Still no start. Air filter is clean as well. Thoughts??? Have no more hair to lose.