Cummins 4089270 Fuel Injector Assembly

The 4089270 fuel injector is a high-pressure common rail injector assembly designed for Cummins B Series, ISB, and QSB engine platforms ranging from 3.9L to 6.7L displacement. Manufactured by Bosch to Cummins OEM specifications, this component ensures precise fuel atomization and injection timing control for optimal combustion efficiency. Technical construction features a solenoid-actuated nozzle assembly calibrated for specific flow rates matching Cummins calibration codes. The injector body incorporates hardened steel internal components resistant to wear from ultra-low sulfur diesel and biodiesel blends. Critical sealing surfaces are precision ground to maintain high-pressure integrity up to system rail pressures. OEM cross-reference interchange includes Cummins 3939696, 3939396, 4088416, and Bosch 0432133787. Remanufactured variants typically carry suffix RX (e.g., 3802748RX, 4089270RX). This injector serves as a direct replacement for factory-installed units on industrial, agricultural, and construction equipment powered by compatible Cummins engines.