How do you adjust the injection timing of 4DR5 diesel engine?

To adjust the injection timing of a 4DR5 diesel engine, first, ensure the engine is at TDC (top dead center) for the number one piston on the compression stroke. Then, loosen the injection pump mounting bolts and rotate the pump slightly to advance or retard the timing as needed. After making adjustments, tighten the bolts and check the timing using a timing light or appropriate gauge to ensure it meets the manufacturer's specifications. Finally, perform a test run to confirm optimal engine performance.