Canister Purge Control Valve: Description and Operation

Remotely Mounted Or In-line Purge Valve:

This purge control valve is normally closed by spring pressure above the internal diaphragm, and blocks fuel vapors from entering the intake manifold. The valve is located in-line between the canister and a vacuum port on a fitting at the throttle body or at the PCV valve connection.

Vacuum Operated Purge Control Valve:

When ported vacuum to the upper chamber of the purge control valve becomes stronger than the spring, the diaphragm is lifted and the valve is opened. At this point purging vacuum is allowed to pass through the valve and purge the fuel vapors out of the charcoal canister.