Scheme 13
EVAP : Evaporative Emission
Scheme 14
DESCRIPTION
On-Board Refueling Vapor Recovery (ORVR) system is properly designed to prevent the fuel tank vapor (HC) emission during refueling at the gas station. This system consists of fill vent valve (ORVR), fuel shut-off valve, fuel cut valve (roll over), two way valve (pressure/vacuum relief), fuel liquid/vapor separator which is installed beside the filler pipe, charcoal canister which is mounted under the rear floor LH side member with protector, tubes and miscellaneous connections. While refueling, the flow and column of the refueling draws the ambient air into the filler pipe so as not to emit fuel vapor in the air. The fuel vapor in the tank is then forced to flow into the canister via the fill vent valve and the fuel liquid/vapor separator which isolates liquid fuel ingredient and transfers the pure vapor to the carbon canister. While the engine is operating, the trapped vapor emission in the canister is drawn and fed by the intake manifold vacuum into the engine combustion chamber. According to this purge process, the carbon canister is purged and recovers its absorbing capability.
Scheme 15
Scheme 16
OPERATION
Check the gasket of the fuel filler cap, and the filler cap itself, for damage or deformation. Replace the cap if necessary.
Scheme 17
Exhaust emissions (CO, HC, NOx) are controlled by a combination of engine modifications and PCM fuel control.
Modifications to the combustion chamber, intake manifold, camshaft and ignition system form the basic control system. Additional control devices include a catalytic converter and the oxygen sensors which monitor mixture control.
These systems have been integrated into a highly effective system which controls exhaust emissions while maintaining good driveability and fuel economy.