Cummins 4903084PX Fuel Injector Assembly

The Cummins 4903084PX is an Electronic Unit Injector (EUI) designed for the Celect fuel system on non-certified 11-liter M11 series diesel engines. It integrates the pumping element, nozzle, and solenoid valve into a single unit mounted directly in the cylinder head. The injector receives electronic signals from the Engine Control Module (ECM) to precisely meter and time fuel delivery at high pressure. This assembly is engineered for direct replacement on Cummins M11, ISM11, QSM11, ISM, and QSM engine platforms used in heavy-duty trucking, construction machinery, and industrial power generation. It supersedes part numbers 4903084, 3087772, and 4061851. The 4903084RX designation indicates a remanufactured variant calibrated to original factory specifications. Installation requires specific torque procedures and ECM calibration verification via Engine Serial Number (ESN) to ensure correct fueling and emissions compliance.