Evaporative Emissions System: Description and Operation

Evaporative Emissions Control System Schematic:

SYSTEM DESCRIPTION

The Evaporative Emission Control System (EECS) uses the basic charcoal canister storage method. This method transfers fuel vapor from the fuel tank to an activated carbon storage canister. This retains the fuel vapors when the vehicle is not operating. When the engine is running, the fuel vapor is purged from the carbon element by intake air flow, and consumed in the normal combustion process.

Fuel Vapor Canister:

VAPOR CANISTER AND PURGE OPERATION

This evaporative system uses a two tube canister. The fuel vapors vent from the fuel tank to the tube labeled "TANK" on the vapor canister. The canister purge is controlled by a ported vacuum source. The vapors are purged when the engine is running above base idle speed.