Air Flow Measurement

The amount of air entering engine is measured by the air flow sensor. As intake air is drawn past the air flow sensor flap, the spring-tensioned flap opens and in turn actuates a potentiometer inside the sensor. The varying resistance of the potentiometer provides a varying voltage signal, which is approximately 0-5 volts, to the control unit that is proportional to the air flow. The air flow sensor also contains an intake air temperature sensor that measures the temperature of incoming air.

The throttle is operated by the accelerator pedal via the accelerator cable, and controls the amount of air drawn in by the engine. The throttle is adjusted during manufacture and does not require any routine adjustment. If the factory settings have been tampered with, then the throttle can be readjusted. The throttle switch is mounted to the underside of the throttle housing. Whenever the throttle is fully closed or fully open is when the throttle switch sends a voltage signal to the control unit.