Abstract: A method and apparatus for desulfating a NOx trap is proposed wherein the SOx purge temperature is achieved by modulating the amplitude of the A/F of the mixture supplied to the engine thereby storing oxygen in the trap during lean engine cylinder events and generating the required exotherm during rich engine cylinder events.

Abstract: A method and apparatus for desulfating a NO.sub.x trap is proposed wherein the SO.sub.x purge temperature is achieved by modulating the amplitude of the A/F of the mixture supplied to the engine thereby storing oxygen in the trap during lean engine cylinder events and generating the required exotherm during rich engine cylinder events.

Abstract: A method and apparatus for desulfating a NO.sub.x trap is proposed wherein half of the engine cylinders are operated at a rich air/fuel ratio and half are operated at a lean A/F during the desulfation process. The two exhaust gas streams, the rich stream and the lean stream, are physically or chemically separated until they enter the NO.sub.x trap. A catalyzed exothermic chemical reaction is then generated in the trap. The resulting temperature increase is sufficient to remove SOX from the trap. During desulfation spark advance is adjusted to minimize event time imbalance.

Abstract: A method and system for controlling combustion stability for a lean-burn engine having a plurality of cylinders including a plurality of cylinder pairs utilizes a speed sensor for sensing an engine speed and generating a corresponding temperature signal and an air flow sensor for sensing a cylinder air mass and generating a corresponding air mass signal. An average event time for each of the plurality of cylinders is determined, as well as an instantaneous variation in event times between each of the plurality of cylinder pairs. An actual level of engine roughness is determined based on the variation in instantaneous event times from the average event times. A desired level of engine roughness is determined based on the speed signal, the air mass signal, and a desired air/fuel ratio.

Abstract: A method and system for determining and controlling air/fuel ratio during lean engine operation relies on applying a small fuel pulse width modulation to the engine and synchronously measuring the effect of the modulation on related engine event periods. This effect is utilized in estimating air/fuel ratio, which is then compared to the desired air/fuel ratio. The difference between the estimated air/fuel ratio and the desired air/fuel ratio is used in controlling the air/fuel ratio to the desired air/fuel ratio.

Abstract: A spark plug for an ignition system has a ring gap between two electrodes. A first electrode has a ring shape defining a central opening. A second electrode is positioned within the central opening of the first electrode. An insulating material is positioned between the first and second electrodes so as to provide a surface for a spark path between the first and second electrodes. The insulating material is spaced from the electrode so as to provide therebetween an air gap for increased sparking.

Abstract: A distributorless ignition system of an internal combustion engine has a supplementary spark energy module to increase spark energy. Two ignition coils each have secondary coils with split secondary center taps. Each of the primary windings is coupled to its own ignition module. The supplementary spark energy module is coupled to each of the split secondary center taps. A pair of spark plugs is coupled to one of the secondary windings and another pair of spark plugs is coupled to the other secondary winding.

Abstract: An ignition system for an internal combustion engine having a capacitive plasma jet plug including a capacitor in parallel with the series combination of an auxiliary gap and a plasma cavity. The auxiliary gap increases the required breakdown voltage before the plasma cavity generates a spark and obtains supplemental energy from the energy stored in the capacitor.

Abstract: A distributorless ignition system of an internal combustion engine has a supplementary spark energy module to increase spark energy. Two ignition coils each have secondary coils with split secondary center taps. Each of the primary windings is coupled to its own ignition module. The supplementary spark energy module is coupled to each of the split secondary center taps. A pair of spark plugs is coupled to one of the secondary windings and another pair of spark plugs is coupled to the other secondary winding.

Abstract: The rate of change of throttle position in an internal combustion engine is used to stabilize throttle response when controlling the throttle to a desired position in response to a fuel demand. A constant voltage is generated which controls the throttle position to achieve a direct level of manifold absolute pressure. The constant voltage is equal to the difference between a command voltage representing a desired manifold absolute pressure and a feedback voltage which is the sum of a first product of a first constant and a voltage representing actual manifold absolute pressure and of a second product of a second constant and a voltage representing throttle velocity.

Abstract: A distributorless ignition system of an internal combustion engine has a supplementary spark energy module to increase spark energy. Two ignition coils each have secondary coils with split secondary center taps. Each of the primary windings is coupled to its own ignition module. The supplementary spark energy module is coupled to each of the split secondary center taps. A pair of spark plugs is coupled to one of the secondary windings and another pair of spark plugs is coupled to the other secondary winding.

Abstract: An ignition system for a stratified charge internal combustion engine is disclosed. The engine has at least one combustion chamber and a fuel injection means effective to inject fuel in a conical spray pattern into a predetermined zone of the combustion chamber for establishing a stratified charge. The system has walls dening a plasma ionizing chamber with an outlet orifice, electrical discharge means to apply an electrical charge across the plasma ionizing chamber causing the contents thereof to be shock heated to an ionized condition and released through the outlet orifice as a jet, and means interrupting the outlet orifice to form said plasma jet into a hollow cone and to direct the conical jet into the zone of the injected fuel.

Abstract: Capacitor discharge ignition system for a spark-ignition internal combustion engine. The ignition system employs an ignition coil having primary and secondary windings wound on a ferromagnetic core, preferably made of a ferrite material. A first capacitor is connected in series with a spark gap and this series combination is connected across the ignition coil secondary winding. The ignition coil primary winding has a second capacitor coupled to it which capacitor is charged and then discharged in timed relation to engine operation. The first capacitor and ignition coil windings and construction are selected such that the second capacitor when discharged through the ignition coil primary winding produces ferroresonant oscillations in the secondary circuit of the ignition coil. This breaks down the spark gap and an alternating voltage, at the ferroresonant frequency, occurs.