Description

The Cummins Injector 3919331 (7 mm) is a precision-engineered diesel fuel injector designed to deliver accurate fuel atomization and consistent injection timing , ensuring efficient combustion and reliable engine performance in Cummins diesel engines. This injector is a direct replacement for Cummins OEM part number 3906699 , making it ideal for injector replacement, fuel system service, and complete engine rebuilds. Manufactured to OEM specifications , this 7 mm injector is built using high-quality materials capable of withstanding high fuel pressures, elevated combustion temperatures, and continuous heavy-duty operation . The precisely machined nozzle and internal components ensure uniform spray patterns, improved fuel efficiency, reduced emissions, and smooth engine operation. Designed for accurate fitment and dependable fuel delivery , the Cummins 3919331 injector helps restore proper engine power, throttle response, and combustion stability. Replacing worn or failing injectors during an engine overhaul or fuel system service is critical to preventing rough idle, misfires, excessive smoke, and premature engine wear. This injector is commonly used in Cummins diesel engine rebuild, overhaul, and fuel system repair applications , including on-highway trucks, industrial engines, and heavy-duty equipment requiring reliable fuel injection performance.