ENGINE AND EMISSION CONTROL PARTS DESCRIPTION - Throttle Sensor & Soft Idle Switch (Cont'd), Fuel Injector, Pressure Regulator, Exhaust Gas Sensor

The fuel injector is a miniaturized, lightweight, solenoid valve. As the E.C.U. sends injection signals to the injector, the flat valve is pulled back and fuel is released into the intake manifold with two directions of spray. The amount of fuel injected is controlled by the E.C.U. in terms of the injection pulse duration.

The pressure regulator maintains the fuel pressure at 299.1 kPa (2.991 bar, 3.05 kg/cm², 43.4 psi). Since the injected fuel amount depends on injection pulse duration, it is necessary to maintain the pressure at the above value.

The exhaust gas sensor, located in the exhaust manifold, monitors the oxygen level in the exhaust gas. This sensor is made of zirconia. The potential difference across the sensor changes with the density of oxygen and supplies a voltage signal to the E.C.U. The heater in the sensor operates at 12V with 11W power consumption, and stabilizes performance of the engine during starting.