Abstract: In order to prevent occurrence of engine stall even when a quick braking is made in a state where a torque converter of an automatic transmission is locked up, the torque converter is locked up in accordance with a throttle opening degree and a vehicle speed, and the lock-up is released at least when the braking operation is carried out. The opening degree B of an idle speed control valve (ISCV) for bypassing a throttle valve simultaneously with the lock-up is set, and the opening degree B is set as an actual control opening degree IV of ISCV when the opening degree B is larger than the opening degree IAV of ISCV which is set in accordance with the load of an engine. When the release of the lock-up is started, the actual control opening degree IV is gradually reduced to the opening degree IAV by a prescribed attenuation amount K. As a result, the engine stall due to a response delay to the release of the lock-up clutch can be prevented.

Abstract: A control method is provided for an engine for a vehicle. The engine is arranged in association with a fluid coupling having a clutch. According to the control method, the state of engagement of the clutch is first detected. In the next step, it is determined whether or not the vehicle is in a predetermined decelerated operation state. When the clutch has been detected to be in a predetermined state of engagement in the clutch engagement state detection step and in addition, the vehicle has been determined to be in the predetermined decelerated operation state in the decelerated operation state determination step, an output of the engine is increased in the subsequent step.

Abstract: A fuel-cut control system for an automobile is equipped with an engine with a fuel-cut device and an automatic transmission with a lock-up torque converter, and includes a step-by-step fuel-recover device which cooperates with the fuel-cut device and is responsive to transition from coasting to acceleration running, for recovering each of engine cylinders from fuel-cut step-by-step, while continuing a locked-up state of the torque converter in its lock-up range during the transit.

Abstract: A horsepower limiting engine control limits the maximum engine horsepower output during operating conditions that might result in torque outputs that are greater than the transmission component ratings. The control includes an electronic controller connected to solenoid driver circuitry, an engine speed sensor and a gear selector. The solenoid driver circuitry energizes a solenoid in response to an engine speed less than a first predetermined engine speed value. The solenoid causes a moveable stop to retract permitting the engine to produce full rated power. The electronic controller causes the solenoid circuitry to de-energize and extend the moveable stop in response to the engine speed exceeding a second predetermined engine speed value and the gear selector being in a predetermined position.

Abstract: An air-fuel ratio control system controls the air-fuel ratio of a mixture supplied to an internal combustion engine. The engine is installed on an automotive vehicle having an automatic transmission provided with a locking-up device. The air-fuel ratio control system controls the air-fuel ratio to a predetermined air-fuel ratio leaner than a stoichiometric air-fuel ratio when the locking-up device is engaged. The air-fuel ratio control system sets the predetermined air-fuel ratio to a value depending on whether the locking-up device is fully engaged or partially engaged.

Abstract: A friction clutch coupling an engine and a gear transmission of a vehicle is controlled by a microprocessor based circuit using logic which defines operating modes according to engine and clutch conditions. During the time of clutch closure, when the vehicle is starting from rest in a startup or launch mode, the throttle or other engine control signal is restrained from quickly responding to the accelerator pedal. This avoids engine overspeeding which results from generating high torque before sufficient clutch capacity has been achieved. The control signal is developed as a function of the pedal position under control of throttle logic which, in turn, is dependent on clutch operating modes defined by the clutch logic.

Abstract: A system for controlling the transient torque output of a multicylinder, variable displacement, spark-ignited, fuel injected automotive internal combustion engine during periods when the effective displacement of the engine is being changed includes a spark timing controller, a throttle controller for positioning an intake air throttle, an engine cylinder operator for deactivating and reactivating at least some of the engine's cylinders, and an engine controller having a processor for selecting the number of cylinders for operation and for operating the spark timing controller, the throttle controller, and the cylinder operator so that during any transition from operation with a first number of activated cylinders to operation with a second number of activated cylinders, the processor will alter the spark advance and control the amount of air entering the engine cylinders so that the torque output of the engine will remain relatively unchanged during the transition.

Abstract: A friction clutch coupling an engine and a gear transmission of a vehicle is controlled by a microprocessor based circuit using logic which defines operating modes according to engine and clutch conditions. During the time of clutch closure, when the vehicle is starting from rest in a startup or launch mode, the throttle or other engine control signal is restrained from quickly responding to the accelerator pedal. This avoids engine overspeeding which results from generating high torque before sufficient clutch capacity has been achieved. The control signal is developed as a function of the pedal position under control of throttle logic which, in turn, is dependent on clutch operating modes defined by the clutch logic.