Abstract: There is provided a spark plug testing kit for safe and convenient testing of petrol engines. The testing kit has a spark observation device within which a spark gap of a spark plug installed therein may be observed in use. The kit has a positive lead for connection to the engine distributor and an earth lead configured for connection to a spark plug opening engaging device. The spark plug engaging opening device comprises threading for turning into a spark plug socket of an engine block and defines an elongate male electrical connection nut standing proud therefrom over which a corresponding electrical connection of the earth lead may be easily and safely electrically connected. The spark plug engaging opening device further comprises exhaust ports through a side of the device for engine decompression during cranking.

Abstract: The method and apparatus of the present invention are useful for the monitoring of the electrical signals within an internal combustion spark plug circuit and the killing of a spark plug within that circuit. The invention essentially consists of connecting a transformer to the high voltage side of the spark plug circuit. Through the use of impedance and inductance, the present invention can either produce a low voltage replica of the waveform of the high voltage electrical signal which is directed to a spark plug or can effectively prohibit that spark plug from firing by short circuiting the low voltage side of the transformer of the device.

Abstract: An inductive ignition apparatus for a combustion engine includes a measurement device for ascertaining the ionization current at the spark plug of each cylinder, and includes for each spark plug an ignition coil device which forms the ignition high voltage, operates on the transformer principle, and has a primary and a secondary winding, and through whose secondary winding the ionization current flows. A switch is provided which short-circuits the primary winding for the duration of the ionization current measurement.

Abstract: A tester for testing the spark plugs, distributor system, and wires used on combustion engines. The tester includes a housing that has an opening therethrough adapted and dimensioned for receiving a spark plug therethrough. The housing has at least one open face. A grounding rod is inserted through the aperture of the housing. The grounding rod is adapted for abutting a spark plug. A grounding wire is electrically connected to the grounding rod, which is adapted for coupling to a ground.

Abstract: With a transistor ignition system, in order to generate an ion current measurement signal at the secondary end, the ignition transistor, following an ignition triggering impulse, will be driven such that a saw-toothed collector current results as a primary current, and whose rate of increase is selected such that the quasi-stationary direct voltage generated hereby at the secondary end will not trigger any ignition process. The advantage is that for generating such a measurement signal as well as for its evaluation only a few components are required.

Abstract: A new and improved spark plug testing apparatus is in the form of an electrically conductive, metallic spring clip and includes a pair of first electrically conductive contact portions for contacting an electrically conductive externally threaded portion of a spark plug. A first resilient portion is connected to the pair of first electrically conductive contact portions for clamping the first electrically conductive contact portions onto the electrically conductive externally threaded portion of the spark plug. A pair of second resilient portions is connected to the respective first electrically conductive contact portions, and a pair of second electrically conductive contact portions is connected to the respective second resilient portions, such that the first resilient portion urges the second electrically conductive contact portions onto an electrically conductive internally threaded portion of a spark plug receiving aperture on an internal combustion engine.

Abstract: The apparatus for measuring spark plug ignition current to monitor combustion in an internal combustion engine includes a spark plug having a spark plug housing containing a spark plug insulating body (12), a pin-shaped central electrode located in the spark plug housing, a ground electrode held in the spark plug housing insulated from the central electrode so as to cooperate with the central electrode and a current measuring resistor (19) for measuring an ignition current of the spark plug. The ground electrode is grounded by electrical connection to the spark plug housing (10) via the measuring resistor (19). The ignition can be monitored by measuring the ignition current passing through the measuring resistor, since the ignition current must pass directly and entirely through the measuring resistor, and the combustion occurring can be assessed from the measured ignition current.

Abstract: An ignition system interface for interposing an automotive combustion engine having a computer controlled ignition with an engine test analyzer. The interface receives timing signals from the ignition computer and generates modified timing based on command from the engine analyzer. Modified timing signals are transmitted to the coil ignition module which fires the spark plugs of the engine. The analyzer may command a shorting of the cylinder which causes the interface to modify the timing at the appropriate time for inhibiting a selected cylinder from firing. Secondary signals from the spark plugs are received by the interface and converted to a proper voltage waveform for recognition by the engine analyzer. The cylinder No. 1 is monitored by the interface and converted to a proper waveform for transmission to the analyzer.

Abstract: An internal combustion engine performance analyzing system is disclosed for displaying a number of operating characteristics, such as engine ignition and cylinder power, which exists under selectively controlled operating conditions. Simple connections to the engine provide the necessary signals to the solid-state electronic analyzer. Various pattern display modes may be selected. An anticipatory cylinder fire signal, which is related to crankshaft rotational degrees, permits a given cylinder to be shorted for the desired interval, regardless of the engine speed. This anticipatory cylinder fire signal is obtained from a servoed ramp waveform generator. Individual cylinder waveform patterns are synchronously and simultaneously displayed on an oscilloscope.