Internal combustion engine with exhaust gas recirculation and mixture control

摘要

An internal combustion engine for a motor vehicle has an exhaust gas recirculation system for returning exhaust gases into the intake port. The carburettor system comprises a fuel enrichment valve (6). Sensors for different speeds of travel and engine operating states actuate control valves, the action of which is modified by a sensor (Sa) for atmospheric pressure. In this way the fuel enrichment valve (6) and a valve (16) in the exhaust gas recirculation duct are controlled so that the fuel enrichment and the exhaust gas recirculation can both be reduced when the vehicle is operated at high altitude at low atmospheric pressure.