Abstract: A reactant delivery system for engine exhaust gas treatment may include a tank in which a reactant is received, a pumping device, a pressure relief device, and a reactant distribution device. The pumping device may have an inlet disposed within the interior of the tank to receive the reactant, and an outlet through which the reactant is discharged. The pressure relief device may have an inlet in fluid communication with the outlet of the pumping device, a primary outlet to discharge the reactant under pressure to a downstream location, and a bypass outlet through which at least some of the reactant discharged from the pumping device is selectively discharged. And the reactant distribution device may be in fluid communication with the bypass outlet of the pressure relief device and have a plurality of outlets to distribute the reactant to at least two different locations within the tank.

Abstract: A reactant delivery system for engine exhaust gas treatment may include a tank in which a reactant is received, a pumping device, a pressure relief device, and a reactant distribution device. The pumping device may have an inlet disposed within the interior of the tank to receive the reactant, and an outlet through which the reactant is discharged. The pressure relief device may have an inlet in fluid communication with the outlet of the pumping device, a primary outlet to discharge the reactant under pressure to a downstream location, and a bypass outlet through which at least some of the reactant discharged from the pumping device is selectively discharged. And the reactant distribution device may be in fluid communication with the bypass outlet of the pressure relief device and have a plurality of outlets to distribute the reactant to at least two different locations within the tank.

Abstract: A reactant delivery system for engine exhaust gas treatment may include a tank in which a reactant is received, a pumping device, a pressure relief device, and a reactant distribution device. The pumping device may have an inlet disposed within the interior of the tank to receive the reactant, and an outlet through which the reactant is discharged. The pressure relief device may have an inlet in fluid communication with the outlet of the pumping device, a primary outlet to discharge the reactant under pressure to a downstream location, and a bypass outlet through which at least some of the reactant discharged from the pumping device is selectively discharged. And the reactant distribution device may be in fluid communication with the bypass outlet of the pressure relief device and have a plurality of outlets to distribute the reactant to at least two different locations within the tank.

Abstract: An adaptive closed loop fuel control system generates an index of maturity value which indicates the extent to which parameters which characterize an individual engine have been learned and stored for future use in a non-volatile memory. A timer produces the index of maturity value by measuring the elapsed time during which the fuel control system has successfully operated the engine at or near stoichiometry within a predetermined range of engine speed and load conditions. A backup mechanism counts the number of HEGO sensor state changes as the closed loop controller operates in an adaptive mode, setting the index of maturity to a predetermined value even when the measured adaptation time fails to indicate an adequate amount of adaptive operation.

Abstract: An electronic ignition timing system which cooperates with an adaptive closed loop fuel control system to provide more rapid heating of an exhaust catalyst by retarding the ignition tinning during colds starts only after an index of maturity value has been generated to indicate that fuel control parameters which characterize an individual engine have been adaptively learned and are available to operate the engine with a lean mixture during cold idling conditions. The index of maturity value alters the mode of operation of the fuel control mechanism to provide robust rich operation prior to adaptation and a more aggressive lean mode operation after the adaptive parameters have been developed which permit optimized operation, and alters the ignition timing to retard the spark to more rapidly heat the exhaust catalyst.