B Series Truck 2WD L4-2184cc 2.2L 2200 2-bbl (1990)
Pulsair Valve: Description and Operation
Air Injection System (AIS)
This system supplies secondary air into the exhaust system to burn (oxidize) CO and HC in the exhaust gas and to control the oxygen signal for the
engine control unit.
Reed valve "A" supplies secondary air into the exhaust manifold when the No. 1 or No. 2 air control valve passage opens, and when both are open.
Reed valves "B" and "C" supply secondary air into the exhaust pipe just behind the front catalytic converter through exhaust gas pulsation.
The air injection system consists of: ACV solenoid valve, air control valves, reed valves, oxygen sensor, coolant temperature sensor, idle switch,
ignition coil, emission control unit, and coolant temperature switch.
ACV SOLENOID VALVE
The ACV solenoid valve applies vacuum to the No. 2 air control valve according to a signal from the emission control unit.
AIR CONTROL VALVES
No. 1 air control valve supplies secondary air to reed valve "A" according to intake manifold vacuum. No. 2 air control valve supplies secondary air
to reed valve "A" when the ACV solenoid is on.
REED VALVES
Reed valve "A" supplies secondary air to the exhaust manifold. Reed valves "B" and "C" supply secondary air to the exhaust pipe just behind the
front catalytic converter.
ENGINE CONTROL UNIT
The engine control unit detects engine speed, engine coolant temperature, intake manifold vacuum, atmospheric pressure, radiator coolant
