Toyota Air-Mix Type Two-Hole Injector for 4-Valve Engines

An air-mix type 2-hole injector has been developed for 4-valve engines. In order to finely atomize the fuel whilst maintaining the separation of the twin sprays that assures minimal wetting of the partition between the siamese ports, the location of the air inlet passages was optimized and studies were conducted to determine the appropriate geometry of the fuel separation portion of the adapter. High speed photographs verify that the finalized adapter realizes centralized fuel flow through the splayed conduits so that the maximum air entrainment is achieved.

This new injector both improves transient response and reduces HC emissions under all temperature conditions. It further enables injection timing to be retarded to the intake stroke at the same low HC level.