Abstract: A thin film coating for a low allow steel or tool steel components in a fuel injector (14), such as a fuel injector needle valve (86) is disclosed. A thin film coating (96) consists of a metal carbon material layer less than 2.0 microns thick applied to a low alloy steel substrate (95) or tool steel substrate (95) used in fuel injector components, such as the fuel injector needle valve (86) or a portion thereof. Optionally, a thin bond layer (98) of chromium is deposited between the steel substrate (95) and the primary metal carbon material coating (96). The thin film coating (96) minimizes abrasive and adhesive wear associated with the needle valve (86) and cooperating nozzle surfaces (62,63) of the fuel injector (14).

Abstract: A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. One of the needle valve members moves to an open position while the other needle valve member remains stationary for a homogeneous charge injection event. The former needle valve member stays stationary while the other needle valve member moves to an open position for a conventional injection event. One of the needle valve members is at least partially positioned in the other needle valve member. Thus, the injector can perform homogeneous charge injection events, conventional injection events, or even a mixed mode having both types of injection events in a single engine cycle.