IGNITION TIMING CONTROL SYSTEM IN ENGINE

摘要

A system is disclosed for controlling the ignition timing for an internal combustion engine on a vehicle. The control effected is designed to increase mileage during low exhaust emission conditions and to better control exhaust emissions under conditions tending to increase such emissions, A double acting vacuum control mechanism is indirectly responsive to engine vacuum through a control valve arrangement which selects either increased advancement or increased retardation with increased engine vacuum as a function of the operating conditions of the engine. The operating conditions of the engine which determine the selection of the control valve position are vehicle speed and the degree of steady state operation referred to as cruising conditions.