My line of work is highway construction, and I’m surrounded daily by diesel-powered equipment. When a machine runs out of fuel, my day usually begins to suck pretty quickly.
Fuel-injected cars have fuel pumps in or near their fuel tanks to feed the fuel (typically gasoline) to their engines. Diesel equipment generally does not.
Your diesel engine probably has two pumps – a main fuel pump and an injector pump. Both are likely mechanical pumps located on the engine. The difficulty level of priming the pumps, once dry, can vary dramatically. Some main pumps have a manual priming lever, some don’t. If yours has one, try that first. If it doesn’t, you’ll probably have to resort to loosening the injector lines to allow the system to purge itself of air past the injector pump. In extreme cases, we’ve had to loosen the lines at the injectors.
Good luck, and watch that fuel guage!