EXHAUST EMISSION CONTROLE.G.R. System The E.G.R. (Exhaust Gas Recirculation) System has exhaust gases recirculate into the combustion chamber and lowers the combustion temperature so as to reduce NOx produced in combustion process. An E.G.R_. control valve measures the amount of exhaust gases recirculating from the exhaust mani~ fold to the intake manifold by vacuum pressure in th carburetor. The thermal vacuum valve is Io- ed midway between the vacuum passage and E.G.R. control valve. This valve is adopted to prevent engine from losing stability when the water temperature is low. With the engine at idle or at full throttle, the E.G.R. control valve closes to deactivate the E.G.R. system regardless of water temperature (operation of the thermal vacuum valve). Description Water temperature is below 50C (122 F) E.G.R. VC Don rm... E.G.. valvuJ lClosed) To intakt manifold f Exhau gas from Thermal vacuum valve exhaust manilold (Cloud, SECIZE Water temperature is above 50" C (122 F) Carburetor P Throttle valve E.G.R. VC port Ta inuk manual: 1 Wu 9 "7" Athermal vacuum valve exhaust manimla (open, seclasr