Research of an Electronic CNG Engine Control System

An electronic CNG engine control system was developed and its high-energy electric ignition, CNG supply system and electronic control unit were designed. The three-way catalytic converter was used to reduce the exhaust emission by the method of theoretical air-fuel ratio control. The MC68HC912 was chosen as the center for ECU and the electronic spark switch circuit, TBI injection valve driver were also designed for controlling ignition timing and multi-point sequential injection quantity of CNG. The ECU was designed especially for high reliability and anti-disturb ability. Engine bench tests showed that the e-lectronic Control system is practical.