Abstract: A circuit for improving the resolution of an oxygen sensor in a vehicle exhaust system. The circuit expands a limited output voltage range of an oxygen sensor to full voltage range of an analog-to-digital (A/D) converter, prior to input of the expanded signal into the A/D converter. Utilization of the full range of converter provides improved resolution for analyzing the analog signal.

Abstract: A piston and cylinder assembly according to the invention includes a cylinder block having a cylinder defined by a cylinder bore wall, a cylinder head connected to the cylinder block, and a piston for reciprocating in the cylinder relative the cylinder head. A combustion chamber for an air/fuel mixture has a volume formed by the cylinder bore wall, cylinder head, and the piston, and is divided into an intake side and an exhaust side by a longitudinal center axis of the piston. A spark plug is mounted in the cylinder head and extends into the combustion chamber to ignite the air/fuel mixture therein. A crown of the piston has a raised peak offset from the longitudinal center axis for providing a homogeneous air/fuel mixture in the combustion chamber near the spark plug.

Abstract: A method of determining a goal voltage for a fuel/air sensor of an engine electronic fuel injection system includes the steps of determining a goal fuel/air sensor voltage, superimposing a wave form forcing function to the fuel/air sensor voltage for providing a goal fuel/air sensor voltage having a wave form pattern and controlling the engine to operate according to the goal fuel/air sensor voltage. The wave form forcing function provides the required fuel/air perturbations that are required to retain proper oxygen storage of the catalyst to maintain high three-way conversion efficiency.

Abstract: A method for reducing hydrocarbon emissions in an engine of a vehicle. The methodology is triggered following the switching off of the ignition by the operator. First, fuel delivery to the engine is terminated. Second, spark ignition is continued based on a predetermined parameter such as time or engine cycles following the termination of the fuel delivery. Last, spark ignition is stopped. Since combustion continues until no fuel exists in the cylinder, there is no over abundance of fuel in the catalyst at a subsequent start up. As such, the catalyst operates effectively at start up and hydrocarbon emissions are lowered.

Abstract: An exhaust system is provided including two catalysts and three oxygen sensors. The second catalyst is disposed downstream of the first catalyst. The first oxygen sensor is disposed upstream of the first catalyst, the second oxygen sensor is disposed downstream of the first catalyst and upstream of the second catalyst, and the third oxygen sensor is disposed downstream of the second catalyst. A goal voltage corresponding to a desired level of oxygen within the exhaust is provided for the third oxygen sensor based on engine RPM and MAP. The engine controller compares the goal voltage to an actual voltage generated by the third oxygen sensor and an error value is obtained and converted into a goal voltage for the second oxygen sensor. The engine controller compares the goal voltage to an actual voltage generated by the second oxygen sensor and an error value is obtained and converted into a goal voltage for the first oxygen sensor.

Abstract: An exhaust system is provided including two catalysts and three oxygen sensors. The second catalyst is disposed downstream of the first catalyst. The first oxygen sensor is disposed upstream of the first catalyst, the second oxygen sensor is disposed downstream of the first catalyst and upstream of the second catalyst, and the third oxygen sensor is disposed downstream of the second catalyst. A goal voltage corresponding to a desired level of nitrous oxide and hydrocarbon within the exhaust is provided for the third oxygen sensor. This goal voltage is based on engine RPM and MAP. The engine controller compares the goal voltage to an actual voltage generated by sensing the level of oxygen downstream of the second catalyst. Based on this comparison, an error value between the goal voltage and the actual voltage is obtained. This error value is converted into a goal voltage for the first oxygen sensor.

Abstract: The analog input of a sensor is connected to a 10-bit analog-to-digital converter. The converted is powered using a 5V supply. The A/D is interfaced with a microprocessor; however, only the least significant eight bits of the A/D output are connected to the microprocessor input. The microprocessor is used to adjust the fuel-air mixture used in engine combustion based on the output of the sensor. The use of the 10-bit A/D interfaced with only eight bits allows increased precision and increased computational speed. The increased precision allows more accurate adjustment of the fuel-air mixture to enable the engine to run closer to its stoichiometric point.

Abstract: A fuel control system is provided including a fuel tank, a purge vapor canister, a vapor line, and a fuel injector connected to an internal combustion engine. A purge vapor canister vent valve seals the purge vapor canister from the atmosphere such that the fuel tank, purge vapor canister, and fuel injector form a closed system. Upon initial starting of the engine, the purge vapor pressure is such that the purge vapor is drawn to the fuel injector from the dome portion of the fuel tank after passing through the purge vapor canister. Simultaneously therewith, the amount of liquid fuel is reducing or increasing by an amount of equally increasing or decreasing, respectively, vapor fuel so that a necessary mass flow rate is achieved to support combustion. As the amount of fuel vapors decreases to a negligible amount, combustion is supported by the atomization of liquid fuel.

Abstract: A methodology of computing a combustion stability value and using the combustion stability value to control engine operation is provided. The combustion stability value is determined by monitoring engine operation. The combustion stability value is compared to an expected combustion stability value. Where the combustion stability value is greater than the expected combustion stability value, combustion of the internal combustion engine is controlled as a function of the combustion stability value. Where the combustion stability value is not greater than the expected combustion stability value, combustion of the internal combustion engine is controlled as a function of an O2 sensor value. In either case, engine control is accomplished by modifying a target fuel injection value.

Abstract: A method is provided for controlling the delivery of fuel to an engine of an automotive vehicle equipped with a dynamic crankshaft fuel control system and an oxygen sensor feedback based fuel control system. The method includes determining an averaged combustion metric from the dynamic crankshaft fuel control system. The combustion metric is compared to an allowable engine roughness value and a dynamic crankshaft fuel control fuel multiplier is adjusted based on the comparison via a proportional-integral-derivative control calculation. Thereafter, the integral term of the dynamic crankshaft fuel control system's proportional-integral-derivative control calculation is stored.

Abstract: A method is provided for controlling spark advance based on a fuel modifier. Initially, engine fueling is reduced according to a known dynamic crankshaft fuel control (DCFC) methodology. As a result, the engine tends to run rougher. In response, spark advance is varied based on the overall fuel multiplier reduction from the DCFC methodology. For instance, a look-up table, or mathematical function based on the DCFC multiplier can be utilized as the basis for the spark advance.

Abstract: A method is provided for enriching a fuel to air ratio in an engine during acceleration based on a known fuel multiplier. Initially, the method retrieves the fuel multiplier from a dynamic crankshaft fuel control (DCFC) system. This system uses the fuel multiplier to reduce the amount of fuel delivered to the engine. When acceleration is desired, the method increases the overall acceleration enrichment values as a function of the DCFC fuel multiplier. Thus, when the vehicle is launched via a throttle tip-in while the DCFC system is active, the acceleration enrichment values are increased thereby improving drivability by having combustion taking place in a richer environment.

Abstract: A method is provided for adaptively determining a torque-related (K-factor) value for a torque converter in a vehicle and providing adaptive torque management to an automatic transmission. The torque-related K-factor value is computed for a given torque converter as a function of engine speed and difference in torque measured with the vehicle operating in idle neutral and drive. The vehicle dynamically learns the K-factor value and manages torque applied to the transmission by limiting the engine output speed as a function of the learned torque-related K-factor and vehicle speed.

Abstract: In an engine exhaust system including a DC power source, an apparatus and method for electrically heating a catalyst, the apparatus comprising a multi-phase AC alternator in electrically operable relation to the DC power source, the AC alternator rectifying the AC to DC by a diode rectifier bridge. A device for switching power supplied from the multi-phase AC alternator to the battery to the electrically heated catalyst, the relay device in electrically operable relation with the multi-phase AC alternator. An electrically heated catalyst in electrically operable relation with the switching device is also provided, the catalytic converter including a catalyst for purifying exhaust gases of the engine and a heating element for bringing the catalytic converter expediently within peak operating temperature. The invention further includes a device for energizing and de-energizing the switching device, the energizing and de-energizing device in electrically operable relation with the switching device.

Abstract: A method of determining start of closed-loop fuel control for an internal combustion engine including the steps of determining a base fuel pulsewidth threshold, ascertaining whether a current accumulated base fuel pulsewidth is greater than or equal to the base fuel pulsewidth threshold, updating the current accumulated base fuel pulsewidth with a value of a previous accumulated base fuel pulsewidth plus the current base fuel pulsewidth if the current accumulated base fuel pulsewidth is not greater than or equal to the base fuel pulsewidth threshold, and beginning a closed loop fuel control of a plurality of fuel transferring components if the current accumulated base fuel pulsewidth is greater than or equal to the base fuel pulsewidth threshold.