Abstract: An apparatus for reducing noxious gases in the exhaust emissions of an automobile is disclosed. During engine cold start, a cold start injector having a heater downstream of the injector outlet vaporizes fuel so that a leaner air-fuel mixture can be used, thereby reducing engine emissions before the engine and catalytic converter warm up. The heater includes various configurations for swirling the fuel and exposing it to large surface areas for improving the vaporization of the fuel. A tapered bore surrounding the throttle allows for precise air flow control into the cold start device during engine warm-up.

Abstract: A fuel management system for a gaseous fuel internal combustion engine is disclosed in which a mass air flow sensor as well as a mass gas flow sensor provide input signals to an electronic control unit (ECU) which then determines the air/fuel ratio. The ECU in turn generates output signals to a fuel valve to control the mass of fuel flow to the engine and thus the air/fuel ratio. A turbocharger bypass valve, a precooler for the gaseous fuel supply, a pressure accumulator upstream from the fuel valve, as well as a system to calibrate the engine to the specific gaseous fuel is described to enhance the accuracy of the fuel management system. An improved pressure balanced valve for controlling the fuel flow to the engine is also provided as well as a cylinder pressure transducer to optionally provide an output signal to the ECU to determine the air/fuel ratio.

Abstract: A fuel control system is provided for use with an internal combustion engine having at least one cylinder, a source of gaseous fuel and an intake passageway for fluidly connecting the air intake to the combustion cylinder. The control system includes a gas flow rate sensor which generates an output signal representative of the fuel flow rate to the engine as well as a mass air flow sensor which generates a signal representative of the mass air flow rate to the engine. A fuel valve is fluidly connected in series between the source of gaseous fuel and the air intake passageway. The fuel valve is actuated by an electrical pulse stream between an open and a closed position so that the duty cycle of the pulse stream is proportional to the amount of fuel supplied to the engine. In response to the fuel flow rate signal, the air flow rate signal and a target air/fuel ratio, the control system generates PID gain scheduling parameters relative to the duty cycle of the pulse stream.

Abstract: A fuel management system for a gaseous fuel internal combustion engine is disclosed in which a mass air flow sensor as well as a mass gas flow sensor provide input signals to an electronic control unit (ECU) which then determines the air/fuel ratio. The ECU in turn generates output signals to a fuel valve to control the mass of fuel flow to the engine and thus the air/fuel ratio. A turbocharger bypass valve, a precooler for the gaseous fuel supply, a pressure accumulator upstream from the fuel valve, as well as a system to calibrate the engine to the specific gaseous fuel is described to enhance the accuracy of the fuel management system. An improved pressure balanced valve for controlling the fuel flow to the engine is also provided as well as a cylinder pressure transducer to optionally provide an output signal to the ECU to determine the air/fuel ratio.

Abstract: A cold start fuel control system as provided for an internal combustion engine of the type having at least one combustion chamber, an intake manifold and a source of fuel. A fuel vapor canister has an interior chamber fluidly connected to the source of fuel and a normally closed shut-off valve fluidly connected between the canister and ambient air. A normally closed purge valve is then fluidly connected in series between the interior of the canister and the intake manifold. The system also includes a cold start fuel injector having an inlet connected to the fuel source and an outlet open to the intake manifold or, optionally, to the interior of the fuel vapor canister. During a cold start engine condition, fuel is supplied as needed from both the fuel vapor canister and cold start injector by activating the cold start injector and simultaneously opening the purge and shut-off valves in synchronism with the engine intake cycle(s).

Abstract: A fuel management system is provided for use with an internal combustion engine which utilizes gaseous fuel as the fuel source. A mass gas flow sensor is fluidly connected between the gaseous fuel source and the engine. A mass air flow meter is similarly provided in series with an air intake for the internal combustion engine and the outputs from both flow meters are provided as input signals to a microprocessor based control circuit. The control circuit calculates the air/fuel ratio of the combustible charge provided to the engine and generates appropriate output signals to a valve arrangement in series between the source of gaseous fuel and the internal combustion engine to vary the air/fuel ratio to obtain a desired engine performance as a function of the engine operating condition. An air/fuel ratio sensor is also in fluid communication with the exhaust gas stream from the engine and provides an output signal representative of the actual air/fuel ratio to the control circuit.

Abstract: A sensor is disclosed for detecting the relative air/fuel ratio of the exhaust gas from an internal combustion engine. The sensor includes a housing which defines a closed interior chamber. An oxygen diffusion cell constructed of a solid electrolytic material has one side exposed to the exhaust gas and a second side exposed to the housing chamber so that oxygen ions flow through the diffusion cell in dependence upon the relative oxygen concentration in both the exhaust gas and the internal air chamber. A sense cell constructed of a solid electrolytic material also has one side exposed to the air chamber and a second side exposed to a substantially constant source of oxygen, such as the atmosphere. Thus, oxygen ion flow through the sense cell varies as a function of the oxygen concentration in the air chamber and thus of the oxygen concentration in the engine exhaust gas.

Abstract: A system for reducing knock in an internal combustion engine is disclosed and includes a vibration detector which detects engine vibration and generates an output signal representative of the magnitude of the engine vibration over a predetermined frequency spectrum. The vibration output signal multiplied by a first weight factor is integrated over a lower portion of the frequency spectrum to obtain a first value while the vibration signal multiplied by a second weight factor is integrated over a higher portion of the frequency spectrum to obtain a second value. The first value is compared with a first threshold value and, when the first value exceeds the first threshold, the system generates a fuel control output signal to increase the fuel supplied to the engine to reduce engine knock.