Abstract: An engine ignition and control system for an internal combustion engine. The system includes an ignition transformer mounted to a spark plug and adapted to rapidly re-fire the spark plug during a combustion cycle enabling the performance of various engine diagnostic procedures. A controller provides a signal to an ignition circuit which causes the transformer to charge for ignition and subsequently charge for performing diagnostics. The system also includes a diagnostic circuit, connected to the transformer, which can detect the occurrence of an electrical discharge across the spark plug electrodes as a result of one of the diagnostic charges. The detections circuit either outputs a signal to the controller or omits the signal to the controller. This allows the controller to diagnose conditions within the combustion cylinder.

Abstract: An engine ignition and control system for an internal combustion engine. The system includes an ignition transformer mounted directly to a spark plug and adapted to rapidly refire the spark plug during a combustion cycle enabling the performance of various ignition diagnostic procedures. A controller provides signals to a circuit which causes charging of the transformer for ignition and subsequent charging of the transformer for diagnostic purposes. The system also includes a diagnostic circuit, connected to the transformer, which can detect the occurrence of electrical discharges across the spark plug electrodes as a result of the diagnostic charges. The detection circuit either outputs a signal or omits a signal to the controller which allows the controller to diagnose conditions within the combustion cylinder. Additionally, the diagnostic circuit is capable of outputting a signal which can be correlated to the load on the engine.

Abstract: A method for determining engine load of a spark ignition internal combustion engine. The method includes the steps of charging an ignition transformer to a maximum ignition charge and initiating an ignition discharge between electrodes of the spark plug. The ignition transformer is then charged to a predetermined diagnostic charge which is less than said maximum ignition charge. The diagnostic charge is discharged at a time of the combustion cycle where pressure in the combustion cylinder is dependent on engine load. The duration diagnostic discharge is then monitored and subsequently correlated to engine load. In this manner, the spark plug is used as a feedback element in determining engine load.

Abstract: A method for detecting misfire in the combustion cylinder of a spark ignition internal combustion engine. The method includes the steps of charging an ignition transformer to a maximum ignition charge and initiating an ignition discharge between electrodes of the spark plug. The ignition transformer is then charged to a predetermined diagnostic charge which is less than said maximum ignition charge. If combustion is occurring within the cylinder, the temperature and pressure near the spark plug will be sufficient to allow the diagnostic charge to discharge. If the diagnostic charge does not discharge, the charge will be reflected back into the ignition transformer where it will be detected by a circuit as an indicia of misfire.

Abstract: An ignition and engine control system for an internal combustion engine. The system includes a flyback ignition transformer which can rapidly re-fired a spark plug during a combustion cycle to perform various ignition diagnostic procedures using the spark plug as a feedback element of the control system. The transformer is adapted for mounting directly to a spark plug and includes a core about which a primary and secondary are toroidally wound. A controller provides signals to a circuit which causes maximum charging of the transformer for ignition and subsequent charging of the transformer for diagnostic purposes. The system also includes a diagnostic circuit which can detect the occurrence of an electrical discharge, and/or its duration, across the spark plug as a result of one of the diagnostic charges by monitoring the transformer for a reflected voltage in its primary.