Accord L4-1751cc 1800 EK1 (1982)
Pulsed Secondary Air Injection: Description and Operation
Fig.160 - Secondary Air Supply System
This system, Fig. 160, makes use of vacuum pulses in the exhaust manifold to draw air from the air cleaner to the exhaust manifold, to prevent the
catalytic converter from overheating. When the vehicle speed exceeds the set speed of the speed sensor and the manifold vacuum is above the set
vacuum of the control switch, the control switch solenoid valve and the control switch are open, therefore the manifold vacuum is applied to the air
suction diaphragm valve to open the secondary air passage. When vacuum induced by the pulsation in the exhaust manifold makes the air suction
reed valve open, the fresh air pours into the exhaust manifold. The bellows of the control switch compensates the switch operation in response to
the atmospheric pressure. Air chambers act as silencers to reduce the exhaust noise.
