Abstract: An apparatus is provided for monitoring ignition in individual cylinders of a multi-cylinder engine of the type having an ignition system which includes a separate transformer for each cylinder. Each transformer has primary and secondary coils. The secondary coil is connected in series with a spark gap in an associated one of the cylinders. The ignition system further includes selector switches for receiving cylinder select signals and responsively connecting respective transformer primary coils. The current flows through the primary coil resulting in a voltage potential across an associated spark gap which normally increases to a magnitude sufficient to cause a spark across the spark gap. A first circuit receives the cylinder select signals, senses time delay between the reception of a cylinder select signal and sparking in a respective cylinder and responsively produces a delay signal indicative of the sensed time delay.

Abstract: An apparatus (8) is provided for controlling ignition in an engine having a ignition system (10), an engine cylinder sensor (48), and a piston disposed in the cylinder and being movable to a top dead center (TDC) position. The cylinder sensor (48) produces a first signal representing the position of the piston within the cylinder and having a frequency responsive to engine speed. The ignition system (10) includes a transformer (24) having a primary coil (26) which is energized in response to a cylinder select signal to produce sparking across an associated spark plug gap (22). A first circuit (98) is provided for sensing a delay between production of the cylinder select signal and the time at which current through a respective primary coil exceeds a preselected current level, and responsively producing a timing error signal.