Abstract: An engine roughness sensor for generating speed normalized digital roughness signals indicative of the variations in magnitude between successive torque impulses imparted to the engine's crankshaft by measuring the period or time it takes the crankshaft to rotate through the same angle for each torque impulse is disclosed herein. The digital roughness signal is normalized as a function of engine speed by dividing the measured magnitude of each torque impulse by a signal indicative of the engine speed to reduce the magnitude of operator induced variations in the generated roughness signals. In an alternate embodiment, the disclosed engine roughness sensor generates a second difference roughness signal which is the difference between the sequentially generated roughness signals.

Abstract: A single point fuel injection system for an internal combustion engine including a throttle body having first and second air intake throats corresponding to first and second intake manifold planes of the engine, the air flow through each throat being controlled by throttle plates positioned within each throat. The throttle body further includes a fuel accumulating bowl which is integrally formed with the throttle body, the bowl being enclosed by a diaphragm and cover member. Within the enclosure of the fuel bowl are positioned a pair of injectors which are adapted to inject pulsed portions of fuel through a sonic nozzle and into the air intake throat of the throttle body. The injection of pulses of fuel into the throat is timed in accordance with the sensing of the crankshaft reaching a position of 15.degree. before top dead center to enhance the distribution of fuel charge from cylinder to cylinder.

Abstract: Closed loop timing and fuel distribution controls for an internal combustion engine operative to control the timing and fuel delivery to each engine combustion chamber is disclosed herein. The closed loop timing and fuel distribution controls are closed about the instantaneous rotational velocity of the engine's output shaft and generate timing and fuel correction signals operative to modify the timing functions of the engine as well as the quantity of fuel delivered to each of the engine's combustion chambers. The control generates from the crankshaft's instantaneous rotational velocity a profile of each torque impulse imparted to the engine's output shaft and computes the phase angle signal indicative of the phase angle of each torque impulse to generate a timing correction signal indicative of the difference between the computed phase angle signal and a desired phase.

Abstract: An idle speed control valve for use in controlling the idle speed of an engine wherein the control valve utilizes a pilot valve to control a valve lift assist force generated by a pressure acting on a differential area associated with the valve. The control valve is actuated in response to a desired speed signal generated by sensed engine conditions as compared to the actual speed of the engine.

Abstract: A single point fuel injection system for an internal combustion engine including a throttle body having first and second air intake throats corresponding to first and second intake manifold planes of the engine, the air flow through each throat being controlled by throttle plates positioned within each throat. The throttle body further includes a fuel accumulating bowl which is integrally formed with the throttle body, the bowl being enclosed by a diaphragm and cover member. Within the enclosure of the fuel bowl are positioned a pair of injectors which are adapted to inject pulsed portions of fuel through a sonic nozzle and into the air intake throat of the throttle body. The injection of pulses of fuel into the throat is timed in accordance with the sensing of the crankshaft reaching a position of 15.degree. before top dead center to enhance the distribution of fuel charge from cylinder to cylinder.

Abstract: An integrated closed loop engine control is disclosed in which the fuel delivery and timing functions of the engine are closed about a measurement of the engine's instantaneous rotational velocity. Signals indicative of the profile of each torque impulse imparted to rotary output member of the engine from the burning of an air/fuel mix in the engine's combustion chambers are generated and electrically analyzed to detect perturbation caused by deviations of at least two different engine operational parameters from desired values. Feedback correction signals indicative of the magnitude of the detected perturbations are generated to correct the fuel delivery and timing functions of an engine control to minimize the difference between the actual operating parameters and the desired values.

Abstract: A closed loop engine roughness fuel control for an internal combustion engine operative to maintain the operation of the engine at a predetermined roughness level is disclosed herein. The control measures two rotational intervals within each torque impulse imparted to the engine's crankshaft by the combustion process and generates a speed normalized engine roughness signal indicative of the engine's actual roughness. The engine roughness signal is multiplied by the engine speed and summed with a reference signal to generate a bias signal operative to modify the quantity of fuel being delivered to the engine maintaining the operation of the engine at a predetermined roughness level. A signal indicative of the first derivative of the engine speed is also summed with the reference and roughness signal to compensate for false roughness signals generated during transient modes of operation.

Abstract: An engine roughness sensor for generating speed normalized digital roughness signals indicative of the variations in magnitude between successive torque impulses imparted to the engine's crankshaft by measuring the period or time it takes the crankshaft to rotate through the same angle for each torque impulse is disclosed herein. The digital roughness signal is normalized as a function of engine speed by dividing the measured magnitude of each torque impulse by a signal indicative of the engine speed to reduce the magnitude of operator induced variations in the generated roughness signals. The disclosed engine roughness sensor generates a second difference roughness signal which is the difference between the sequentially generated roughness signals.

Abstract: A method and apparatus for controlling the various functions of an internal combustion engine using a program controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules, such as a fuel cut-off and reset system which responds to one of the selected fail signals receives information concerning one or more engine operating parameters such as manifold pressure, throttle position, engine coolant temperature, air temperature, and engine speed or period and the like. These parameters are sensed and then supplied to input circuits for signal conditioning and conversion to digital words usable by the microprocessor.

Abstract: In an electronic fuel injection system for an internal combustion engine an oxygen sensor tests the exhaust gas for oxygen content and provides a feedback signal for fuel/air mixture control. During cold start and engine warm-up the oxygen sensor is inoperative and mixture is controlled as a function of engine coolant temperature. During this phase the mixture may be excessively lean causing rough engine running. Means responsive to cylinder misfirings temporarily enrich the mixture to eliminate engine roughness.

Abstract: A closed loop engine control system for internal combustion engines is described. The control system includes a comparator which is responsive to signals indicative of the presence or absence of oxygen in the exhaust gas of the engine and a set point or reference and is operative to generate an output signal for receipt by a fuel delivery controller which will cause that fuel delivery controller to increase fuel delivery in the presence of oxygen molecules in the exhaust gas and to decrease fuel delivery in the absence of oxygen molecules in the exhaust gas in order to maintain the fuel delivery at the predetermined, and preferably the stoichiometric, air/fuel ratio mixture point. An oscillatory stabilization signal is also applied to the comparator to reduce the amplitude of the limit cycle.

Abstract: A fuel injector (10) is provided for each cylinder of an internal combustion engine, the injector including an electronically operated control valve (146) disposed between supply passage 42 and a timing chamber (98) to control the admission of fuel into and out of the timing chamber. A primary pumping plunger (62) and a secondary plunger (90) are axially spaced within the central bore of the injection body, and a normally closed injection nozzle (14) is situated at one end of the injector body. A mechanical linkage (27, 28, 30) associated with the camshaft of the engine drives the primary pumping plunger (62) against the bias of a main spring (18). The timing chamber (98) is defined between the plungers (62, 90) and a metering chamber (128) is defined between the secondary plunger (90) and the nozzle (14).

Abstract: A method and apparatus for controlling the various functions of an internal combustion engine using a program-controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine-operating parameters such as manifold pressure, throttle position, engine coolant temperature, air temperature, and engine speed or period and the like. These parameters are sensed or measured and then the value thereof is supplied to input circuits for signal conditioning and conversion to digital words usable by the microprocessor.

Abstract: A closed loop control system is disclosed for controlling the air-fuel ratio of an internal combustion engine. An oxygen sensor is connected into the control loop after engine warm up when the temperature has reached its operating temperature to maintain the air-fuel ratio close to the stoichiometric value. An engine roughness detector is connected into the control loop before the oxygen sensor has reached its operating temperature to maintain the air-fuel ratio close to a predetermined lean limit. A temperature sensor and switching means controlled thereby are provided to alternately connect the roughness detector and the oxygen sensor in the control loop.

Abstract: A method and apparatus for controlling the various functions of an internal combustion engine using a program-controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine-operating parameters such as manifold absolute pressure, throttle position, engine coolant temperature, air temperature, and engine speed or period or the like. These parameters are sensed and then supplied to input circuits for signal conditioning and conversion into digital words usable by the microprocessor.

Abstract: A method and apparatus for controlling the various functions of an internal combustion engine using a program-controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine operating parameters such as manifold absolute pressure, throttle position, engine coolant temperature, air temperature, and engine speed or period and the like. These parameters are measured and then supplied to input circuits for signal conditioning and conversion to digital words usable by the microprocessor. The microprocessor system computes a command word indicative of a computer-commanded engine control operation and output circuitry responds to predetermined computer-generated commands and to the computed digital command words for converting them to corresponding pulse-width control signals for controlling such engine operations as fuel-injection, ignition timing, proportional and/or on-off EGR control, and the like.

Abstract: A flow regulating device for use in a single-point control electronic fuel injection system. The flow regulating device receives a discrete, pressurized fuel pulse or charge from a fuel injector and extends its time duration over the charge cycle period to approximate a continuous flow. The extended fuel charge is provided to an atomizer for mixture with air preparatory to being drawn into an engine intake manifold. In one embodiment of the invention, the flow regulating device includes a constant pressure valve together with a restricted flow passage. The pressure setting of the valve is below the pressure at which the discrete fuel charge is emitted from the injector, and the restricted passage has an orifice dimension smaller than that of the injector nozzle. In another embodiment of the invention, the flow regulating device takes the form of a pair of parallel connected constant pressure valves together with restricted flow passages.

Abstract: A method and apparatus for controlling the various functions of an internal combustion engine using a program-controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules. The microprocessor-based control system receives information concerning one or more engine-operating parameters such as manifold absolute pressure, throttle position, engine coolant temperature, air temperature, and engine speed or period and the like. These parameters are sensed or measured and the analog sensor output signals are supplied to input circuits for signal conditioning and conversion into digital words usable by the microprocessor system.

Abstract: A method and apparatus for controlling the various functions of an internal combustion engine using a program-controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine operating parameters such as manifold pressure, throttle position, engine coolant temperature, air temperature, and engine speed or period and the like. These parameters are sensed and then supplied to input circuits for signal conditioning and conversion to digital words usable by the microprocessor.

Abstract: A pressure sensor including a pressure capsule such as a dual diaphragm quartz capacitance pressure capsule. The pressure capsule having two parallel quartz plates spaced by a dielectric ring forming a vacuum chamber therein.A registration fixture is described which contains a plurality of flat plates, each plate having a pressure capsule receiving cavity sized to closely receive one of the quartz plates and further provides a uniform temperature radiation pattern for sealing of the pressure capsule during the controlled pressure-temperature profile.