Abstract: A method and system 10 for reducing cold-start emissions of an automotive vehicle 12 having an internal combustion engine 26. System 10 includes a main controller or control system 14, a variable valve timing system 16, an ignition system 18, a fuel metering system 20, and vehicle operating condition sensors 22. Controller 14 detects cold-start conditions based on signals received from sensors 22, and in response to such a detection, controller 14 generates command signals to said variable valve timing system 16, to said ignition system 18, and to said fuel metering system 20, effective to respectively alter valve timing, spark timing, and said air/fuel delivery of engine 26 in a manner which synergistically increases air/fuel enleanment limits, improves combustion characteristics, and increases exhaust gas temperature, thereby reducing cold-start emissions.

Abstract: Air/fuel and ignition control of engine are used to more rapidly heat-up a catalytic converter. A control system generates a fuel command for fuel delivery to the engine based upon at least an amount of air inducted into the engine. The fuel command is corrected by a correction value so that the exhaust gas mixture is shifted more closely to the preselected air/fuel ratio. Correction values are adaptively learned during warm engine operation from a feedback signal derived from an exhaust gas oxygen sensor. Initial warm correction values are stored in a reference table. At engine shut-off the difference between the warm correction values and the reference table are stored in an offset correction table. This offset correction table is then used during the next engine cold start to schedule the open-loop air/fuel ratio by using the cold adaptive table values which have been modified by the values stored in the corresponding cells of the offset correction value table.

Abstract: A catalyst system employed in the exhaust stream of an internal combustion engine (10) wherein the catalyst deterioration is monitored by an engine controller (26) connected to a first oxygen sensor (22) mounted upstream of a catalyst (18) and a second oxygen sensor (24) mounted downstream. After a cold start of the engine (10) a calibration of the first and second sensors is conducted, to assure accuracy between the two sensors and determine if one of the sensors has failed, and also a light-off time for the catalyst (18) is determined as one way to measure the deterioration of the catalyst. After the engine (10) has warmed up to operating temperature, a test is run to determine the ability of the catalyst (18) to store oxygen therein, being another indication of catalyst deterioration.

Abstract: A method and system for determining a quantity of fuel to be injected into a multi-cylinder, internal combustion engine during each combustion event of the engine includes an air flow sensor for sensing a quantity of air flowing through the engine. An electronic control unit is operative to determine a desired combustion fuel quantity based on the quantity of air flowing through the engine and determine a desired fuel injection quantity based on a previous fuel injection quantity delivered during a previous combustion event and the desired combustion fuel quantity. The control unit is further operative to control the amount of fuel injected into the engine for the current combustion event based on the desired fuel injection quantity.

Abstract: A catalyst system employed in the exhaust stream of an internal combustion engine (10) wherein the catalyst deterioration is monitored by an engine controller (26) connected to a first oxygen sensor (22) mounted upstream of a catalyst (18) and a second oxygen sensor (24) mounted downstream. After a cold start of the engine (10) a light-off time for the catalyst (18) is determined as one way to measure the deterioration of the catalyst. After the engine (10) has warmed up to operating temperature, a test is run to determine the ability of the catalyst (18) to store oxygen therein, being another indication of catalyst deterioration.

Abstract: A method for accelerating the rotational speed of a crankshaft of an internal combustion engine having a plurality of cylinders each having a spark plug wherein a predetermined amount of delivered fuel is to be combusted at a firing time within each of the plurality of cylinders with each rotation of the camshaft or crankshaft based on an acceleration input made by an operator includes the step of receiving the accelerating input, measuring the rotational speed of the crankshaft, defining an expected engine speed based on the acceleration input, calculating a speed error as the rotational speed of the crankshaft less the expected engine speed, calculating engine acceleration and adjusting the predetermined amount of fuel delivered to be combusted in each of the plurality of cylinders to reduce the speed error when the speed error is a function of the instantaneous engine speed. The preferred embodiment is implemented using fuzzy logic.

Abstract: A method and system for determining and controlling air/fuel ratio during engine cold start operation relies on applying a monotonically decreasing 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 method for maintaining the rotational speed of a crankshaft of an internal combustion engine having a plurality of cylinders each having a spark plug wherein a predetermined amount of delivered fuel is to be combusted at a firing time within each of the plurality of cylinders with each rotation of the camshaft or crankshaft includes the step of operating the internal combustion engine, measuring the rotational speed of the crankshaft, defining an expected engine speed, calculating a speed error as the rotational speed of the crankshaft less the expected engine speed, and changing the predetermined amount of delivered fuel to be combusted in each of the plurality of cylinders to reduce the speed error. The preferred embodiment is implemented in fuzzy logic.

Abstract: A catalyst system employed in the exhaust stream of an internal combustion engine (10) wherein the catalyst deterioration is monitored by an engine controller (26) connected to a first oxygen sensor (22) mounted upstream of a catalyst (18) and a second oxygen sensor (24) mounted downstream. After a cold start of the engine (10) a calibration of the first and second sensors is conducted, to assure accuracy between the two sensors and determine if one of the sensors has failed, and also a light-off time for the catalyst (18) is determined as one way to measure the deterioration of the catalyst.

Abstract: A system for the just-in time scheduling of camshaft timing for an internal combustion engine. A slave circuit generates an execution period corresponding to the execution period of the variable camshaft timing mechanisms. The control processor initiates the calculation of a correction signal base on the difference between the desired camshaft timing and the actual camshaft timing synchronous with the execution period of the variable camshaft timing mechanism. The calculation of the correction signal is executed by the central processing unit once and only once for each execution period of the variable camshaft timing mechanism.