Methods and systems are provided for restarting an engine following an engine idle-stop. In one example, a method may include, prior to an engine restart following an idle-stop, adjusting a spark ignition timing based on an estimation of a fuel-air equivalence ratio (phi) and an estimation of a cylinder turbulence. Optimal spark ignition timing based on estimated phi and cylinder turbulence during engine restart may result in stabilized combustion and a torque output sufficient to at least partially relieve demand on the starting device.

A system and method for modifying the engine pull-up (EPU) logic within a hybrid vehicle based on max motor torque that accounts for the drop or change in available motor torque due to the opening/slipping of a torque converter bypass clutch during engine starts is disclosed. An engine pull-up threshold is determined from max available motor torque at a virtual impeller speed, where the virtual impeller speed is the impeller speed that would result if the torque converter bypass clutch was open/slipping and transferring the same amount of torque.

A system and method includes a paving machine, a vehicle, and one or more controllers. The paving machine includes an engine for powering the paving machine and the vehicle is associated with the paving machine. The one or more controllers are configured to determine an estimated time of arrival for the vehicle at the paving machine based on a location of the vehicle; identify a startup time for the paving machine, wherein the startup time comprises a time period between starting the engine of the paving machine and an operational parameter of the paving machine reaching a threshold value; and generate an indication to shut down the engine of the paving machine if the startup time for the paving machine is less than the estimated time of arrival of the vehicle associated with the paving machine.

A powertrain system includes a port injection internal combustion engine. A first start process is a process in which fuel is enclosed in a compression stroke cylinder when the engine is stopped, and based on a stored crank stop position, ignition is performed in a first cycle of the compression stroke cylinder upon engine start. A second start process is a process in which, based on the stored crank stop position, fuel injection is performed for an intake stroke cylinder while the engine is stopped, and based on the stored crank stop position, ignition is performed in the first cycle of the intake stroke cylinder upon engine start. When a catalyst temperature at the time engine start is requested is equal to or higher than a first threshold, a control device starts the internal combustion engine by at least one of the first start process and the second start process.

An engine includes a single cylinder, at least one sensor, a fuel injector, and a controller. The at least one sensor is configured to generate sensor data for an engine condition. The controller is configured to perform a comparison of the engine condition to a threshold and in response to the comparison, generate a first command to deactivate the fuel injector after a first predetermined time period and a second command to reactivate the fuel injector after a second predetermined time period.

A stop/start system and method for an engine of a vehicle include a valve control system configured for full lift control of respective intake and exhaust valves of a plurality of cylinders of the engine and a controller of the engine configured to perform an engine stop event including initiating a fuel shutoff (FSO) event whereby fueling to the engine is disabled and the engine fully stops after a stop period and, in response to initiating the FSO event, commanding the valve control system to close each intake valve prior to closing its respective exhaust valve to (i) expel any residual gases from the cylinders during respective exhaust strokes prior to closing the respective exhaust valves, and (ii) prevent air-only intake and compression within the cylinders during the stop period to thereby mitigate or eliminate noise/vibration/harshness (NVH) caused by the air-only intake and compression.

A method includes determining a value of an operational motor current limit and setting a value of a startup current limit equal to a predetermined value in excess of the value of the operational motor current limit if a set of predetermined conditions is satisfied. The method includes determining that operation of the engine has been interrupted, operating the electric motor of the variable valve timing mechanism with a current having a magnitude that is less than or equal to the startup current limit after determining that operation of the engine has been interrupted, determining that operation of the engine has resumed, and operating the electric motor of the variable valve timing mechanism with a current having a magnitude that is less than or equal to the operational motor current limit after determining that operation of the engine has resumed.

A method is disclosed for controlling an engine assembly comprising an internal combustion engine and an exhaust gas treatment apparatus. The aftertreatment assembly may require cleaning from time to time, and where this involves active thermal management of the aftertreatment assembly, the method involves performing the following steps: (a) imposing a first limit on engine speed; (b) awaiting an engine safe state; and (c) implementing a cleaning process comprising: (i) injecting fuel into the engine such that the fuel passes through the engine without combusting for the fuel to combust in the diesel oxidation catalyst so as to target an increase in exhaust gas temperature in the diesel oxidation catalyst; and (ii) removing the first limit on engine speed and targeting an engine speed set point, wherein the engine speed set point is at a higher speed than the first limit on engine speed.

An engine includes a single cylinder, at least one sensor, a fuel injector, and a controller. The at least one sensor is configured to generate sensor data for an engine condition. The controller is configured to perform a comparison of the engine condition to a threshold and in response to the comparison, generate a first command to deactivate the fuel injector after a first predetermined time period and a second command to reactivate the fuel injector after a second predetermined time period.

Systems and methods for starting and restarting an engine of a vehicle are disclosed. Power systems for an engine are disclosed.