Abstract: An internal combustion engine performance analyzer is described for providing a numerical value representing certain operating characteristics such as spark plug ionization voltage, points closed voltage drop, alternator ripple output voltage and voltage drop across the starter during cranking. Simple connections to the engine provide the necessary signals to the solid state electronic analyzer. The analyzer includes appropriate switches, converters and a cylinder identification circuit in the form of a ring counter for enabling the several parameters to be conveniently measured and displayed in a digital format.