Exhaust Emissions System - Air Injection System: Operation: Midget
The belt-driven air pump supplies air under pressure through the one-way check valve to a single entry point in the exhaust manifold. The air combines with exhaust gases to continue the oxidation process in the exhaust system. The one-way check valve prevents reverse flow in the air injection system when exhaust gas pressure exceeds air pump pressure. A relief valve is attached to the air pump to relieve excess pump pressure at high engine speeds. See Fig 1.