The evaporative emission control system prevents fuel vapours generated
in the fuel tank from escaping into the atmosphere.
Fuel vapours from the fuel tank flow through the fuel tank pressure control valve and vapour pipe/hose to be stored temporarily in the canister.
When driving the vehicle, fuel vapours stored in the canister flow through the gurge control solenoid valve and purge port and go into the intake manifold to be sent to the combustion chamber.
When the engine coolant temperature is low or when the intake air quantity is small (when the engine is at idle, for example), the engine control unit turns the purge solenoid off to shut off the fuel vapour flow to the intake manifold.
This does not only insure the driveability when the engine is cold or running under low load but also stabilize the emission level.
Fuel vapours from the fuel tank flow through the fuel tank pressure control valve and vapour pipe/hose to be stored temporarily in the canister.
When driving the vehicle, fuel vapours stored in the canister flow through the gurge control solenoid valve and purge port and go into the intake manifold to be sent to the combustion chamber.
When the engine coolant temperature is low or when the intake air quantity is small (when the engine is at idle, for example), the engine control unit turns the purge solenoid off to shut off the fuel vapour flow to the intake manifold.
This does not only insure the driveability when the engine is cold or running under low load but also stabilize the emission level.
SYSTEM DIAGRAM
<4G63-SOHC>
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<4G63-DOHC>
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<4G69 Vehicles for Brazil and Chile>
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<4G69 Vehicles for Brazil and Chile>
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NOTE: The evaporative emission ventilation solenoid valve [always OPEN (OFF)],
fuel tank differential pressure sensor, fuel level gauge, fuel temperature sensor are not used
for engine control.