If that engine has K-Line cruise control you will want the instructions to do a reset. There's a specific code for a diesel with K-Line cruise and smoke, and not using the right code can cause it to not move. Unfortunately I don't have the specific code for that engine as I don't have any K-Line diesels with cruise. The information about there being a different code came from the instructions for a steamer with cruise.
One thing to check is that the program/run switch is in RUN position. If it has been inadvertently moved to Program, the engine will not move.