Engine cranks strongly but will not start.
That may indicate a fuel problem.
Check your Shut Down Solenoid to see that it is engaging with the ignition key turned to start. You might be able to hear it engage if standing in the bedroom of your DP when the key is turned.
If it cannot be heard, locate the solenoid and pull up on the arm and wire it open. Then try the ignition. If it starts, check the 12v power to the solenoid or replace the solenoid if power is there but not causing the arm to move.
If the solenoid is fine, try priming the fuel system to remove air and send fuel to the injection pump. I do not know Cat engines but I am sure your manual will tell you.