Engine Running
The purge valve is installed in vacuum line between charcoal canister and throttle valve housing. A vacuum control line is routed from throttle valve housing through a thermovalve and onward to the purge valve.
When the engine is running, throttle valve position is above idle and engine coolant temperature is above 122°F (50°C), canister purging takes place. As the throttle is opened further, more vacuum is applied to the canister and purge rate continues.