System for controlling ignition timing of an internal combustion engine

Claim 1

In a system for controlling ignition timing of an automotive engine mounted on a vehicle, having detector means for detecting engine operating conditions including engine speed and for producing an operating signal dependent on the detected conditions, basic ignition timing calculating means responsive to said operating signal for producing a basic ignition timing, load detecting means for detecting load on said engine and for producing a load signal when the load is larger than a predetermined first load value, advance angle decision means responsive to said load signal for producing an advance angle, desired ignition timing decision means for adding said advance angle to said basic ignition timing and for producing a desired ignition timing, and adjusting means responsive to said desired ignition timing for exciting an ignition coil of said engine to form a spark at a spark plug at the desired ignition timing, the improvement in the system wherein said detector means comprises acceleration detecting means for detecting acceleration of the vehicle and for producing an acceleration signal when the acceleration is larger than a predetermined acceleration value, and said advance angle decision means being arranged to produce said advance angle in response to said load signal and said acceleration signal.