Exhaust gas recirculation system

An exhaust gas recirculation system for an internal combustion engine including an intake passageway having a throttle valve rotatably mounted therein, said system comprising an exhaust gas recirculation (EGR) passage for feeding exhaust gases of the engine into the intake passageway downstream of the throttle valve, a first exhaust gas recirculation (EGR) control valve disposed in said EGR passage, a first actuator operable in response to a vacuum representative of the amount of air drawn through the intake passageway to cause said first EGR control valve to meter the amount of the engine exhaust gases fed into the intake passageway to a predetermined ratio to the amount of said air, a second exhaust gas recirculation (EGR) control valve disposed in said EGR passage downstream of said first EGR control valve, a second actuator operable in response to the vacuum in the intake passageway downstream of the throttle valve and the pressure in said EGR passage between said first and second EGR control valves to cause said second EGR control valve to maintain the pressure differential of parts of said EGR passage upstream and downstream of said first EGR control valve at a predetermined value, passage means to communicate and EGR passage between said first and second EGR control valves with said second actuator, and control means for limiting the amount of the engine exhaust gases passing in said passage means to prevent said passage means from being clogged by the engine exhaust gases.