Operation CHARM: Car repair manuals for everyone.

Air Injection - Operation







OPERATION

During cold start, the air injection system adds a controlled amount of air to the exhaust gases aiding oxidation of hydrocarbons and carbon monoxide in the exhaust stream.

Air is drawn into the pump through a tube that is connected to the mass air flow (MAF) sensor. Airflow is measured by the MAF sensor. A voltage will be produced via the MAF sensor when air is passed through. This voltage correlates to airflow. The amount of voltage (airflow) will determine the amount of fuel that will be added to achieve the goal air/fuel ratio.

Air is then compressed by the air injector pump. It is expelled from the pump into the connecting tube where it reaches the one way check valve and injected into the exhaust manifold.

The one way check valve protects the connecting tube and air pump from hot exhaust gases backing up into the system. Air is allowed to flow through the check valve in one direction only (towards the catalytic converter).