Air Injection System: Description

The air injection system used on the Fiesta is designed to reduce unburned hydrocarbon and carbon monoxide emissions. It does this by injecting fresh air into the exhaust ports to further the burning of hot exhaust gases. The air, which is pressurized by the air pump, enters the exhaust port through an external supply tube. The system consists of an air pump, a by-pass valve, a vacuum vent valve, exhaust check valve, vacuum delay valve and vacuum reservoir. Operations of each are described below.