Basic

Evaporative Emissions






The evaporative emission fuel vapor management system consists of an evaporative emission canister, evaporative emission canister purge valve and an evaporative emission canister purge valve resonator. A combination of plastic pipes and rubber hoses connect the evaporative emission canister to the fuel tank and the evaporative emission canister purge valve to the intake manifold.

On-board refuel vapour recovery (ORVR).






The vehicle is fitted with an onboard refuel vapour recovery (ORVR) type fuel tank. During refuelling all vapour is collected in the evaporative emission canister as well as in normal vehicle operations.

On Federal (USA) specification vehicles the fuel vapor management system uses a canister vent solenoid and a fuel tank pressure sensor which are used during the engine management system on board diagnostic routines.

When the evaporative emission canister purge valve is closed, the fuel tank is vented into the evaporative emission canister through the fuel tank roll-over valve. The evaporative emission canister absorbs the fuel vapor and prevents the release of hydrocarbons into the atmosphere. When the vapor evaporative emission canister purge valve is opened, the canister is exposed to the intake manifold vacuum and the fuel vapor deposits are drawn into the manifold where they mix with the incoming air/fuel charge.

The evaporative emission fuel vapor management system is controlled by the engine control module according to calibrated data tables.