Air Injection: Description and Operation

Air Injection System:

Aspirator Valve:

PURPOSE
Reduces Carbon monoxide (CO) and Hydrocarbon (HC) tail pipe emissions.

OPERATION
The aspirator valve is a one-way spring loaded diaphragm, which is open during negative exhaust pressure (vacuum) pulses.
- While the valve is open it admits air from the air cleaner to enter the exhaust system.
- The added oxygen is used by the catalytic converter to convert HC and CO into CO2 and H2O.
- The aspirator valve works most efficiently at idle and slightly above idle when negative pressure (vacuum) pulses are maximum.

When pressure in the exhaust system is positive, the valve closes and no exhaust gases are allowed to pass, (protecting the rubber hoses).
- At higher engine speeds the aspirator valve remains closed, due to positive exhaust pressure.

CONSTRUCTION
System consists of; an aspirator valve, hose, hose clamps, and tube.