Suction mixture control system for vehicle engines

摘要

An internal combustion engine for a vehicle has an exhaust gas recirculating system for returning exhaust gases to the engine intake passage. The carburetion system for the engine includes a fuel enrichment valve. Sensors for various vehicle speeds and engine operating conditions operate control valves whose actions are modified by a sensor for atmospheric pressure, to control the fuel enrichment valve and a valve in the recirculation passage so that fuel enrichment and exhaust gas recirculation are both reduced when the vehicle travels at a high elevation having low atmospheric pressure.