An engine control system digitally stores corresponding values of timing angles and engine speeds and selects the timing angles based on the operating speed of the engine. In the engine speed range near idle speed, the timing angle is set to a pre-selected angle after top dead center (ATDC) and the relationship...http://www.google.de/patents/US5988139?utm_source=gb-gplus-sharePatent US5988139 - Method and apparatus for controlling an internal combustion engine
