General System Description

DESCRIPTION
The basic Evaporative Emission (EVAP) Control system used on all vehicles is the charcoal canister storage method. This method transfers fuel vapor from the fuel tank to an activated carbon (charcoal) storage device (canister) to hold the 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.

The evaporative system includes the following components:

^ Fuel tank
^ Evaporative emission canister vent solenoid
^ Fuel tank pressure sensor
^ Fuel pipes and hoses
^ Vapor lines
^ Fuel cap
^ Evaporative emission canister
^ Purge lines
^ Purge valve solenoid


Results of Incorrect Operation
Poor idle, stalling and poor driveability can be caused by:

^ Malfunctioning purge solenoid.
^ Damaged canister.
^ Hoses/lines split, cracked and/or not connected properly.