L-Series Wagon 4WD F4-1781cc 1.8L SOHC (Carb) (1987)
Pulsed Secondary Air Injection: Description and Operation
Fig. 27 Air injection system. 4 wheel drive models and all carbureted models
This system, Fig. 27 promotes oxidation of hydrocarbons and carbon monoxide under all operating conditions. It consists of an air suction valve, cutoff
valve, air suction pipe, air introduction hose, air filter, thermosensor, solenoid valve, check valve, and electronic control module.
Exhaust gas pulses are transmitted to air suction valve through air suction pipe. When a negative pressure is present, ambient air flows from air cleaner to
exhaust passage. When positive pressure is present, air switching valve is inoperative.