Abstract: A low cost, easy to use, hand held pulse stream analyzer is designed to show, after an engine stops operating, which pulse stream, ignition or injection, quit first. Additionally, the analyzer is capable, using relative time domain analysis to comparatively analyze these pulse streams to the alternator ripple pulse stream, of determining if the fuel flow to the injectors quit, thus causing the engine to quit. This information quickly gives the technician a direction to investigate to find a responsible faulty component for the problem being experienced, and is especially helpful in attempting to diagnose intermittent faults in a much more efficient manner. The inventive device is usable on virtually all brands and types of gasoline powered vehicles.