In an internal combustion engine, fuel injection is stopped to automatically stop the engine when automatic stop conditions are met. When there is a request to restart the engine while an engine speed is decreasing due to automatic stoppage, the engine is started by resuming fuel injection if the engine speed is equal to or greater than a combustion recoverable rotational speed threshold, at which restarting is possible only by fuel injection. When there is a request to restart the engine while an engine speed is decreasing due to automatic stoppage, the engine is started using a starter motor if the engine speed is less than the combustion recoverable rotational speed threshold. When there is a request to restart the engine in a brake ON state, the engine is not started by resuming fuel injection, but rotated and started using the starter motor.

Provided is a start controller for an engine capable of reducing torque of a starter consumed to start the engine. The start controller includes a stop position sensor that detects a position of a piston in each cylinder at an engine stop time, an intake pressure sensor that detects an intake pressure in an intake passage, and a processor that determines whether the position of the piston in each of the cylinders detected by the stop position sensor is within a specified target range after the engine is stopped. In the case where it is determined that the position of the piston in each of the cylinders after the engine stop is out of the target range and the intake pressure detected by the intake pressure sensor is lower than an atmospheric pressure, the engine is started by a motor even when an engine start condition is not satisfied.

An auto-stop start system for a vehicle. The auto-stop start system has a control unit with an auto-stop start function controlling stop and start of an engine of the vehicle, and a control device by which control device the auto-stop start function can be temporarily deactivated by an operator of the vehicle. The control unit is configured to reactivate the auto-stop start function after a predetermined duration of a temporary deactivation. The predetermined duration of the temporary deactivation of the auto-stop start function is selectable by means of the control device.

In the case of restarting an internal combustion engine that has been automatically stopped during running, the internal combustion engine is restarted by combustion recovery starting when the rotation speed of the internal combustion engine under the input of a restart request is greater than or equal to a predetermined first rotation speed. In the case of restarting the internal combustion engine that has been automatically stopped during running, the internal combustion engine is restarted by cranking recovery starting when the rotation speed of the internal combustion engine under the input of the restart request is lower than the predetermined first rotation speed. The first rotation speed is set lower at the restart of the internal combustion engine in a sailing stop state than at the restart of the internal combustion engine in a coast stop state.

Systems and methods for improving operation of a vehicle are presented. In one example, a controller may respond to a presence or absence of a prediction of an increase in vehicle speed during a look ahead window. The controller may inhibit or allow automatic engine stopping in response to the presence or absence of the prediction of the increase in vehicle speed during the look ahead window.

To prolong a lifetime of a starter battery, a starting system (5) for an internal combustion engine (3) includes: a starter battery (22) constituted of a lithium-ion battery and configured to supply electric power to a starter motor (21); and a controller (51) configured to drive the starter motor (21) by the electric power from the starter battery (22) to perform cranking operations of the engine (3) intermittently, wherein the controller (51) is configured to prohibit the cranking operations for a first time interval before the cranking operations are performed a prescribed number of times within a prescribed time window, and to prohibit the cranking operations for a second time interval longer than the first time interval right after the cranking operations are performed the prescribed number of times within the prescribed time window.

Systems and methods for operating a hybrid vehicle are described. In one example, the automatic engine stopping may be inhibited so that an engine may be restarted during change of mind conditions without generating a large driveline torque disturbance. The engine stopping may be inhibited based on a inhibit engine pull-down torque threshold.

Systems and methods for operating a hybrid vehicle are described. In one example, a torque reserve for starting an engine via an electric machine is adjusted responsive to vehicle operating conditions. The torque reserve may set aside a portion of torque that an electric machine may produce for cranking and starting an engine.

A disclosed method of automatically stopping and restarting a vehicle engine determines if one or more stop/start enablement condition has been met. If the stop/start enablement condition or conditions have been met, the method initiates an engine shutdown. If a restart request is made before the engine reaches a predetermined threshold speed, then a first restart sequence is initiated. If a restart request is made when the engine speed is less than the predetermined threshold speed but still greater than 0, then a second restart sequence is initiated.

An auto-stop start system for a vehicle. The auto-stop start system has a control unit with an auto-stop start function controlling stop and start of an engine of the vehicle, and a control device by which control device the auto-stop start function can be temporarily deactivated by an operator of the vehicle. The control unit is configured to reactivate the auto-stop start function after a predetermined duration of a temporary deactivation. The predetermined duration of the temporary deactivation of the auto-stop start function is selectable by means of the control device.