Fuel Evaporation System: Operation: Notes

The first stage of purge operation occurs when throttle plates are open and a ported vacuum signal is sent to Vacuum Control Valve (VCV). If engine coolant temperature is above 129° F (53° C), ported vacuum signal is sent to No. 1 Purge Control Valve. Manifold vacuum on No. 1 Purge Control Valve draws fuel vapors through an orifice and delivers the vapors to intake manifold.

The second stage of purge operation occurs when engine speed is above 1500 RPM and engine coolant temperature is above 140° F (60° C). The ECA turns on the Canister Purge Control Solenoid and allows vacuum to enter canister purge valve. Manifold vacuum then draws fuel vapors though an additional larger orifice increasing total amount of purge flow.