This fuel injection nozzle delivers a metered spray of diesel into the combustion chamber at the correct pressure and atomization pattern. It is a component of the engine’s fuel delivery system, mounted in the cylinder head and actuated by the high-pressure fuel line. A worn or fouled nozzle causes incomplete combustion, visible as black smoke, reduced power, and increased fuel consumption. Bosch manufactures this nozzle to the original geometry and flow specifications, so it matches the injector body’s seating and cracking pressure without modification. On installation, clean the mounting bore and replace the copper sealing washer.