Fuel Evaporation

EVAP Canister Purge

1. Engine running at idle. At EVAP canister, disconnect vacuum hose from purge valve to canister. Place finger over hose end. No vacuum should be present at idle. Slowly increase engine speed to 3000 RPM. Vacuum should gradually increase with engine speed.
2. If no vacuum was present at hose with increased engine speed, trace hose back to throttle valve housing. Blow through connection on housing to ensure hose and fitting are clear. Retest system. If vacuum is still not present, remove White/Purple/Black hose from purge valve. If vacuum is now present, replace purge valve. If vacuum is still not present, replace thermovalve.