Abstract: An oxygen concentration sensor is disposed in an engine exhaust passageway. The alcohol concentration in the fuel used in the internal combustion engine is detected. A target impedance is set on the basis of the detected alcohol concentration. The actual impedance of a sensor element of the oxygen concentration sensor is detected. The heater output of the exhaust gas sensor is controlled so that the actual impedance becomes equal to the target impedance, whereby the temperature of the sensor element represented by the impedance becomes equal to a target temperature represented by the target impedance.

Abstract: Disclosed is a method for the control and regulation of a V-type internal combustion engine (1), comprising an independent common rail system on the A side and an independent common rail system on the B-side, in which the rotational speed of the internal combustion engine (1) is regulated in a speed control loop and a nominal torque as an adjusted variable of the rotational speed governor is limited during the starting procedure to a starting torque for representing a nominal injection null set.

Abstract: A device for estimating the amount of intake air of an internal combustion engine comprising intake pipe pressure calculation means for calculating an intake pipe pressure, at this time, downstream of the throttle valve, and intake air amount calculation means for calculating the amount of intake air, at this time, based on the intake pipe pressure at this time calculated by said intake pipe pressure calculation means, is provided. The intake pipe pressure calculation means calculates the intake pipe pressure at this time by using the intake pipe pressure calculated at the last time and the amount of air passing through the throttle valve at the last time calculated by means for calculating the amount of air passing through the throttle valve.

Abstract: In a fuel control system for a fuel injected internal combustion engine, fuel is pumped from a tank by a cheek plate unloading pump to the fuel rail which supplies the fuel injectors. The delivery pressure of the pump is controlled by a microprocessor which receives inputs from a number of sensors of engine operating variables. The microprocessor generates a control signal which controls the pump output pressure by actuating a solenoid-type linear actuator. The solenoid has an actuator rod which positions a spool in a control valve which regulates the pressure in a cavity behind the cheek plate in response to the control signal. If there is no control signal from the microprocessor, a spring moves the actuator rod to a position where it partially obstructs a passage through which the pump output flows. The partial obstruction or constriction creates a pressure drop which is proportional to the speed at which the pump is driven by the engine.

Abstract: Method and apparatus are disclosed for controlling fuel flow from a fuel source to the fuel rail of a fuel injected, internal combustion engine. Two fuel flow paths are connected in parallel between the source and the fuel rail, an on-off solenoid valve being provided in each of the fuel flow paths. The two solenoid valves have dissimilar fuel flow capacities. A microcomputer generates a pulse width modulated signal for application to a selected one of the two solenoid valves so as to control fuel flow through the associated fuel flow path. The microcomputer decides to which solenoid valve to apply the pulse width modulated signal and the duty cycle of the pulse width modulated signal in accordance with the value of a master variable. The master variable is adjusted in accordance with the difference between vehicle or engine speed and an associated limit, thereby providing vehicle or engine speed governing. The system is also operable in cruise control and variable engine speed governing modes.

Abstract: A vehicle speed limiting device is designed for use with diesel engines, particularly those in over-the-road trucks. A D.C. pulse generator is attached at the wheel or transmission speedometer pickup and provides a signal to a speed switch which includes a frequency-to-voltage converter which processes the pulse signal. The converter output is then compared to a reference voltage corresponding to a predetermined speed limit, generally 55 miles an hour. When the vehicle speed and corresponding voltage exceeds the reference voltage and speed, the comparator operates a relay which opens or closes a solenoid valve in the fuel supply line of the truck. In most applications, the solenoid valve is placed between the fuel pump and the injector and fuel flow is diverted from the injectors to the upstream side of the pump. A small amount of fuel is allowed to continue to the injectors to provide for proper lubrication thereof.

Abstract: A diaphragm operated, air fuel control system for controlling the rate of fuel flow to an internal combustion engine in response to intake manifold pressure is disclosed wherein the transient response of the diaphragm operator is attenuated by a fuel filled control chamber. An attenuator assembly connected with the control chamber causes fuel to be supplied to the chamber at a rate which is greater than the rate at which fuel may be discharged from the control chamber. In one embodiment the chamber is formed on the side of the diaphragm operator which is opposite to the side to which intake manifold pressure is supplied. In another embodiment the control chamber is formed to receive one end of a plunger valve connected with the diaphragm operator.

Abstract: An improved method and apparatus is provided to control the rate at which fuel is supplied to an engine by a fuel pump. The fuel pump has an output pressure which varies with pump operating speed in accordance with different curves of a series of curves. In order to determine which curve of the series of curves is representative of the manner in which the fuel pump output varies with pump speed at one time, the fuel pump operating speed and output pressure are simultaneously sensed to determine a point on an initial curve. The fuel pump operating speed is subsequently varied in accordance with the initial curve to provide a desired variation in fuel pump output to the engine. The fuel pump operating speed and output pressure are periodically simultaneously sensed to determine if the fuel pump output still varies in accordance with the initial curve or has changed to a second curve of the series of curves.