Air Induction

Air is drawn into the combustion chamber through the air cleaner and intake manifold. The amount of air entering the engine is controlled by the position of the throttle body valve. The throttle body houses the TPS and ISS motor. The TPS is an electrical resistor which is connected to the throttle valve. The TPS transmits a signal to the ECU in relation to throttle valve angle. From this signal, the ECU calculates fuel injector "on" time to provide adequate air/fuel mixture.

The ECU controls the idle speed by providing the appropriate voltage outputs to move the ISS motor pin inward or outward to maintain a predetermined idle speed. The ECU continuously monitors the TPS and ISS motor and issues change commands to the injectors to increase or decrease the amount of fuel injected.