Abstract: A method for controlling fuel vapor purge flow in an automotive type internal combustion engine. The method includes the steps of determining existence of a purge ON condition and determining a simulated engine airflow value. A desired purge flow is calculated as is a value for a desired purge solenoid current. Utilizing a PID control methodology, the desired purge solenoid current is produced and a purge driver generates a PWM signal with to control a purge solenoid with the purge solenoid.

Abstract: A method for monitoring the efficiency of a catalytic converter in a motor vehicle includes the steps of determining if at least one predetermined condition is met for monitoring the efficiency of the catalytic converter. The method includes biasing a fuel feedback multiplier of an internal combustion engine of the motor vehicle to run rich or lean if the at least one predetermined condition is met. The method includes counting a number of switches across a predetermined switch point from an upstream oxygen sensor and a downstream oxygen sensor. The method includes calculating a switching frequency ratio based on the count of the switches from the upstream oxygen sensor and downstream oxygen sensor and using the switching frequency ratio to establish the efficiency level of the catalytic converter.

Abstract: A method of monitoring efficiency of a catalytic converter in a motor vehicle includes the steps of determining if at least one predetermined condition is met for monitoring the efficiency of the catalytic converter and combining a square wave multiplier signal with a feedback multiplier signal if the at least one predetermined condition is met. The method includes counting a number of square wave edges of the combined signal for an upstream oxygen sensor positioned upstream of the catalytic converter and counting a number of switches of a signal across a predetermined switch point from a downstream oxygen sensor positioned downstream of the catalytic converter. The method also includes the steps of calculating a switching frequency ratio based on the count of square wave edges and oxygen sensor switches and using the switching frequency ratio to establish the efficiency level of the catalytic converter.

Abstract: A method and corresponding system for optimizing performance of an internal combustion engine. The present invention senses gases emitted from engine combustion chambers via a first gas sensor and senses gases emitted from said engine combustion chambers subsequent to said gases passing through an engine catalytic converter via a second gas sensor. The temperatures of said first and second gas sensors are then sensed through data output from first and second gas sensors and temperature sensors. The first and second gas sensors are linearized in response to the sensed temperatures of the first and second gas sensors. The fuel level input into the engine combustion chambers is adjusted in response to linearizing of the first and second gas sensors.

Abstract: The fuel delivery control system monitors engine speed and load parameters to develop a wall wetting history that is indicative of the physical state of the fuel within the intake port or intake manifold. The wall wetting history is used along with engine speed, temperature and pressure measurements to determine the pulse width of the fuel injector signal. Fuel to air ratio is thereby optimized. Transient conditions due to changes in engine load or due to acceleration and deceleration are used to generate a pulse width correction signal to optimize performance on a cycle by cycle basis. Each engine cylinder injector may be independently controlled.

Abstract: The present invention is a method for use in a fuel control system for an engine equipped with fuel injectors, where the time when a fuel injector is fired to fuel its cylinder, relative to the cylinder's valve events, may be varied to enable better fuel preparation corresponding to the various engine operating conditions.

Abstract: In a fuel control system for an engine equipped with fuel injectors, a method where the fuel injector is fired to fuel its cylinder, relative to the cylinder's valve events, more than once per cycle if a throttle transient has occurred and caused the original firing of the fuel injector to be less than the fuel amount now required by the new engine operating conditions.