Abstract: An engine air/fuel control system is disclosed having one feedback correction loop generating a feedback variable by essentially integrating the output of an exhaust gas oxygen sensor. A second feedback loop adaptively learns a feedback correction from the difference between the feedback variable and its desired value such as unity. A range of authority for the total air/fuel controller is adaptively learned from the learned correction value to maximize the correction which may be applied by the feedback variable under all operating conditions.

Abstract: An Electronic Engine Controller (EEC) determines the actual dynamic response of an engine which uses a switching type Heated Exhaust Gas Oxygen Sensor (HEGO) by imposing a bias on the air/fuel (A/F) mixture when the engine is operating at steady state conditions and is combusting a stoichiometric A/F mixture. The A/F mixture is then abruptly altered and maintained for a predetermined period of time, and the time elapsed from the abrupt alteration to detection of the abrupt alteration by the HEGO sensor is measured and stored. Upon expiration of the predetermined period of time, the A/F mixture is abruptly altered to the biased A/F mixture and the time elapsed from the abrupt alteration to the biased value to the detection of the abrupt alteration is measured and stored. The bias value is then removed to return the A/F mixture to stoichiometry and the process is repeated for a plurality of bias values. The actual dynamic response of the engine is then determined as a function of the stored time durations.

Abstract: An Electronic Engine Controller (EEC) controls the fuel delivery to an intake of an engine which is equipped with an intake system which includes primary and secondary runners, a primary throttle plate for controlling air flow through both runners and a secondary throttle plate for controlling air flow through the secondary runner. The EEC determines values indicative of the actual and equilibrium amounts of fuel existing in the intake system and controls the fuel delivery based on such values. The actual and equilibrium amounts of fuel include a value indicative of the change in equilibrium fuel due to change in the secondary throttle position.

Abstract: A method and system for generating electronic fuel injection pulse waveforms to achieve an accurate air/fuel ratio control during transient conditions. Sensors are provided for sensing a plurality of engine parameters. An electronic engine controller is provided for performing a plurality of steps associated with the method. The method includes storing calibration data and sensing the engine parameters. A leading edge of the fuel pulse waveform is calculated based on the stored calibration data and the sensed engine parameters. The leading edge of the fuel pulse waveform is generated, thereby triggering an interrupt. Next, a trailing edge of the fuel pulse waveform is calculated based on current fuel mass requirements determined during the duration of the fuel pulse. The method concludes with the step of generating the trailing edge of the fuel pulse waveform.

Abstract: An electronic engine controller (EEC) controls the delivery of fuel to an internal combustion engine via one or more fuel injectors by executing a background routine to measure a plurality of system conditions including airflow and engine temperature. A response value is generated as a function of an aircharge value, the temperature value and a valve effect value. The EEC detects an interrupt which occurs prior to combustion of an air/fuel mixture within each combustion chamber of said engine, and in response to the interrupt execution of the background routine is halted and a foreground routine is executed in which the airflow is measured, an updated aircharge value is generated and the response value is updated as a function of the difference in aircharge values and a predetermined response alteration value. The aircharge value is replaced with the updated aircharge value.

Abstract: An automated method for generating compensation values for use in an electronic engine controller during transient engine operation comprises an initial step of exposing an engine to an ambient temperature value to set the engine to an initial start temperature. The engine is started and operated in a predetermined manner until the engine reaches a stable operating temperature. The mass flow rate of air into an induction system of the engine is detected to generate a plurality of air flow values, the temperature of engine coolant is detected to generate a plurality of engine coolant temperature values and the composition of exhaust gas produced by the engine is detected to generate a plurality of exhaust gas values. The detected air flow values, engine coolant temperature values and exhaust gas values are stored in a data storage means. The engine is exposed to a plurality of ambient temperatures to generate data indicative of engine operation from a plurality of initial start temperatures.

Abstract: An electronic engine controller (EEC) controls the delivery of fuel to an internal combustion engine via one or more fuel injectors by generating a base fuel value and modifying it with a transient fuel compensation value. The EEC determines the transient fuel compensation value by measuring a temperature value indicative of the temperature of the induction system of the engine and determining a valve effect value indicative of the effect of intake valve temperature on the vaporization of fuel in the induction system. A transient fuel compensation value is then generated in response to the temperature value and the valve effect value. The base fuel value, generated under any of a variety of known engine control methods, including open-loop control and closed-loop control, is altered in response to the transient fuel compensation value to generate a fuel injector control signal for controlling the amount of fuel delivered by the fuel injectors.

Abstract: A mass airflow based control system for an internal combustion engine is provided which is capable of inferring cylinder air charge during non-steady state periods of operation of the engine. The control system infers cylinder air charge from values of rotational engine speed, air mass flow inducted into the engine, inlet air temperature, engine coolant temperature, and barometric pressure. The control system employs the inferred cylinder air charge value for air/fuel ratio control.

Abstract: Air/fuel ratio of an internal combustion engine is controlled by predicting the air charge to enter the engine two cylinder events into the future and then determining the amount of fuel to be injected to achieve a desired air/fuel ratio. A first fuel pulse is injected, and if needed, a second fuel pulse is injected to achieve the needed amount of fuel for the desired air/fuel ratio.