Air Injection: Description and Operation

Fig. 8 - Secondary Air Supply System:

Fig. 8b - Secondary Air Supply System:

On all 1980 models & 1981-82 pickups, the reed valve supplies air into the exhaust manifold to further combustion in the exhaust manifold, Figs. 8 & 8b. Vacuum in the exhaust manifold, caused by pulsation of the exhaust valves, actuates the reed valve and supplies air drawn from the air cleaner to the exhaust manifold.

Fig. 8a - Secondary Air Supply System:

On 1981-82 car models, a Pulse Air Feeder is used for supplying secondary air to the exhaust system between the front and rear catalytic converters, to promote oxidation of exhaust gasses in the rear catalytic converter, Fig. 8a. A main and sub reed valve is incorporated in the Pulse Air Feeder. The main reed valve is actuated by a diaphragm which senses pressure pulsations caused by piston movement in the No. 3 cylinder. The sub reed valve is actuated by exhaust gas vacuum caused by pulsation in the exhaust system between the front and rear catalytic converters.