Common problems with the Ford F-350 7.3-liter Powerstroke diesel engine can be the result of normal wear and tear or improper maintenance. The injection pressure regulator valve or injector driver module can suffer damage over time. A clogged fuel filter or bad coolant could also be the culprit.
If the engine is running poorly or cutting out rather than refusing to start, the problem could be the cam position sensor or injection control pressure sensor. Unplug the ICP temporarily to see if the problem goes away; if so, you have isolated the problem. Proper and timely maintenance can prevent or delay many common problems.