Abstract: An apparatus to aid in the testing of engine ignition systems is herein disclosed. The apparatus is connected in a series wiring path between a spark plug wire and a spark plug of an internal combustion-type engine. The apparatus comprises a housing containing a resistor and a lamp which provide illuminated indication of a current flowing through the apparatus. The apparatus allows a user to quickly determine if an ignition circuit of an engine is operating properly.

Abstract: An ignition timing device for timing an engine having a timing port and a timing mark indicative of a position of a movable member. The ignition timing device includes a sensor adapted to be secured in the timing port to provide a timing mark signal indicative of presence of the timing mark. Also, an ignition sensor is adapted to provide an ignition signal indicative of the occurrence of an ignition spark. A filter receives the ignition signal and provides a filtered ignition signal. The filter filters ignition sparks of compression strokes from ignition sparks of compression and exhaust strokes of a selected cylinder to provide the filtered ignition signal. Also, the delay element is provided that receives the filtered ignition signal and provides a delayed signal having a selected delay from the filtered ignition signal. A comparator receives the timing mark signal and the delayed signal.

Abstract: A timing light for measuring timing of spark ignition has separate displays of engine RPM and timing advance. Another aspect of the invention provides a flashlight function which triggers the flash tube of the timing light to produce a constant bright light source for locating timing marks within an engine compartment. The flashlight function can be incorporated into a dual display digital timing light, or other timing light designs. A dedicated control on the timing light functions to place the flash tube in a continuous flashlight mode.

Abstract: A method of detecting spark plug fouling in an internal combustion engine is provided. The method comprises calculating an integration value of discharge current flowing between electrodes of a spark plug during a period of a spark discharge and judging if the calculated discharge current integration value is smaller than an integration value criterion. The integration value criterion is set at such a value that can discriminate between normal discharge and interior jumping (i.e., jumping due to short circuit caused by fouling). When the calculated discharge current integration value is smaller than the integration value criterion, it is judged that the spark plug has been fouled. By this, it becomes possible to detect a spark plug fouling before the electrodes of the spark plug are short-circuited and disabled to generate spark discharge, i.e., before the spark plug is fouled to such an extent as to cause a misfire. An ignition system for detecting spark plug fouling is also provided.

Abstract: A timing light for measuring timing of spark ignition has separate displays of engine RPM and timing advance. Another aspect of the invention provides a flashlight function which triggers the flash tube of the timing light to produce a constant bright light source for locating timing marks within an engine compartment. The flashlight function can be incorporated into a dual display digital timing light, or other timing light designs. A dedicated control on the timing light functions to place the flash tube in a continuous flashlight mode.

Abstract: An ignition timing device for timing an engine having a timing port includes a sensor securable in the timing port to provide a timing mark signal. An ignition sensor is adapted to provide an ignition signal. A comparator receives the timing mark signal and the ignition signal. The comparator provides an output signal indicative of substantial simultaneous occurrence of timing mark signal and the ignition signal. An indicator receives the output signal and is operable as a function thereof.

Abstract: A glow plug controller test device including an electrical connector which can be electrically connected to the vehicle wiring harness connector of the glow plug controller. The test device also includes a pair of leads which are connected to the vehicle power supply and ground, respectively. The test device further includes a light emitting diode which flashes as an indication that the glow plug controller is operational.

Abstract: A high voltage sensor that is adapted to be connected to a terminal. The terminal is disposed in a housing having an outer surface and having a chute extending inwardly from the outer surface to a distal position inside of the housing. The high voltage sensor includes a sensor body that is adapted to be inserted into the chute and has a distal end and a proximal end. A contact is mounted on the distal end of the sensor body. An indicator circuit is substantially enclosed in the sensor body and includes an indicator lamp. The indicator circuit is electrically connected to the contact and the terminal is in electrical contact with the contact upon insertion of the sensor body into the chute of the housing.

Abstract: In combination, a gas turbine engine ignition system exciter, an igniter, a conductor that connects the exciter to the igniter to form a discharge circuit, and a current pulse detector for detecting current pulses in the circuit, the detector comprising a wire disposed in close proximity to a current carrying element in the circuit so that a sense current is induced in the wire across a coreless gap; the detector further comprising a signal conditioning circuit for converting the sense current to an output that indicates occurrence of a spark discharge.

Abstract: A portable hand held diagnostic tool which non-invasively detects an electric field when placed adjacent a component of a spark plug firing portion of an ignition system and provides a positive indication of the detected electric field. A printed circuit board containing a control circuit, a replaceable battery supply, an ON/OFF switch, an indicator such as an LED, and a pickup antenna, is slidably mounted within the hollow interior of a dielectric tubular case. The antenna is located adjacent a pickup end of the case and detects the electric field generated by an ignition system during firing of a spark plug which actuates the LED in response to the detected firing. The dielectric case is free of external metal parts adjacent the pickup end to help minimize arcing. A battery test circuit may be incorporated into the control circuitry to ensure an adequate power supply for operation of the control circuitry. A fixed or variable resistor enables the sensitivity of the firing pickup to be selected.

Abstract: On-board apparatus for visually indicating the efficiency of the spark plugs and ignition wires of an internal combustion engine includes a capacitive clamp attached to the insulated ignition wire of each spark plug of the engine, preferably as close to the spark plug as possible. The current derived by the capacitive clamp is fed through a knock-down resistor to reduce the voltage fed to a conditioning circuit. The conditioning circuit provides a positive pulse substantially proportionate to the intensity of the signal through the conditioning circuit. The resulting signal is then fed to a time delay circuit to provide a relatively smooth signal to a bar graph. The time delay circuit includes high and low sensitivity modes for user selection to generally monitor system efficiency or to detect misfires. An adjustable gain circuit allows the bar graph to be calibrated to operate at a preselected level when the engine idles.

Abstract: A sensor for detecting the firing of a spark plug while maintaining electrical isolation of electronic equipment is disclosed. In the preferred embodiment, a conductive element is attached to one electrical lead of a neon bulb. A wrap secures one end of an optical fiber to the neon bulb for collecting the light from the neon bulb. The optical fiber carries the light from the neon bulb to a data logging device. During use, the conductive element is secured to an insulated spark plug wire and, when the spark plug fires, a voltage between the leads of the neon bulb is induced, causing the neon bulb to produce a pulse of light. The light pulse from the neon bulb is carried by the optical fiber and monitored by the data logging device. By providing an optical fiber to link the data logging device to the neon bulb, electrical isolation is accomplished.

Abstract: A method and device for continuously monitoring the distributed high voltage pulses from an ignition coil of an electrical system of an internal combustion engine is disclosed. The device is a transparent enclosure filled with a noble gas at low pressure. The inner wall of the enclosure is coated with a light emitting phosphor and a small amount of mercury is placed within the enclosure. When the device is placed near a high voltage wire, an electric field capacitively couples to and ionizes the gas within the device. The mercury is excited and emits photons of ultraviolet radiation which in turn creates visible light as the ultraviolet radiation excites the phosphor coating. When this device is placed next to a spark plug wire, it will illuminate when there are high voltage pulses in the wire. In a preferred embodiment two or more enclosures are placed near the same wire. The enclosures contain different gas pressures and are excited at different voltages.

Abstract: A self-contained handheld peak ignition breakdown voltage probe locates faulty sparkplugs in an internal combustion engine. The probe has a novel dual-polarity detection system suitable for all ignition systems, distributorless or distributor types. Each nanosecond peak breakdown ignition event is signalled by a high-intensity LED lamp lit for a fixed period of time. An adjustable calibrated threshold level provides precise control of acceptance level. Other problems such as cabling, plug gap, and relative compression may also be inferred. The simple arrangement of integrated circuits provides a novel and useful tool for locating ignition problems.

Abstract: Engine timing apparatus includes a timing light and a pickup for producing a pickup signal in response to each ignition in a selected cylinder. The operator keys in the desired advance or retard angle in degrees in a range anywhere between +180.degree. and -180.degree.. A program-controlled microcontroller with an internaltimer samples the time period between pickup signals and, using this information and the advance of retard angle, calculates engine rpm and the proper time delay for the flash. The system automatically corrects for system delays to produce extremely accurate timing functions. The system may be used with an inductive pickup for timing gasoline engines or with a luminosity pickup for timing diesel engines. At high rpms the system produces a flash in response to every other pickup signal.

Abstract: An equipment for recognizing misfiring, which is particularly suitable for permanent installation in a motor vehicle. By means of high-pass filters coupled to the plug leads between the spark distributor and the spark plugs, the change to the voltage at the spark plugs associated with the initiation of the ignition spark is sensed. The high-pass filters are so arranged that they only send on a needle-shaped output pulse signal to an analysis circuit if it appears with the change in voltage associated with the spark front. The analysis circuit generates appropriate output signals with reference pulses generated in time with the ignition pulses. The high-pass filters are preferably arranged as simple RC filters whose capacities are coupled to the plug leads by means of peripheral electrodes, which at least partially surround the insulation coatings of the plug leads.

Abstract: A portable electronic device for application in the diagnosis of automotive ignitions system failures is described. A novel probe is described, which can detect and differentiate the voltage on a typical ignition cable or spark plug. Means are provided to shield the differentiating sensor from extraneous fields and to process the differentiated signal to provide simple indications of failure of ignition system components and to identify such components for replacement.

Abstract: A self-contained device for mounting on a motor vehicle, having an internal combustion engine, by means of which the ignition voltages at the spark plugs can be visually monitored by selecting any one of a number of switch points on a manual switch, to connect to a voltage divider at each of the spark plug terminals, by means of which a reduced value of the voltage on the selected device, which will produce a light pulse in synchronism with the occurance of the electrical sparking pulse supplied to the spark plug. The brightness or intensity of the light pulses present, for each of the voltage pulses impressed on the gaseous conduction device, are indicators of the operation of the ignition system.

Abstract: An electric ignition performance monitoring device for permanent installation as an integral part of the ignition system used in conjunction with internal combustion engines wherein light is emitted from sensors when arc current flows across spark plug gaps. Further means are provided for viewing the light from the sensors at a location which is remote from the location of the components of the ignition system but convenient for the operator of the engine, and means for enabling the operator to rapidly determine which particular portion of the ignition system is malfunctioning.