Disclosed is an engine starting control method for a flexible fuel vehicle (FFV) of supplying the heated fuel to the engine by heating an injector heater during cranking when it is determined that cranking condition and fuel heating condition are satisfied at the time of starting the vehicle having a starting auxiliary device for cranking the engine of FFV and a device for heating the fuel using the injector heater provided in an injector, wherein a pre-injection is auxiliary performed prior to a main injection during cold starting of the engine when the heating time of the injector heater exceeds a predetermined value, allowing stable starting with low fuel consumption at a time of cold starting an engine using ethanol fuel in winter.

A system includes an electric machine coupled to an engine and configured to start the engine from an inactive state. A controller executes a first control algorithm while output speed of the electric machine is less than a first speed threshold, and also executes a second control algorithm while the output speed is greater than the first speed threshold and less than a second speed threshold. Additionally, the controller is programmed to execute a third control algorithm while the output speed is greater than the second speed threshold. The first control algorithm includes operating the electric machine using trapezoidal current control with pulse width modulation. The second control algorithm includes operating the electric machine using six-step voltage control with a variable phase advance angle. The third control algorithm includes operating the electric machine using six-step voltage control with a predetermined fixed phase advance angle.

A system includes an electric machine coupled to an engine and configured to start the engine from an inactive state. A controller executes a first control algorithm while output speed of the electric machine is less than a first speed threshold, and also executes a second control algorithm while the output speed is greater than the first speed threshold and less than a second speed threshold. Additionally, the controller is programmed to execute a third control algorithm while the output speed is greater than the second speed threshold. The first control algorithm includes operating the electric machine using trapezoidal current control with pulse width modulation. The second control algorithm includes operating the electric machine using six-step voltage control with a variable phase advance angle. The third control algorithm includes operating the electric machine using six-step voltage control with a predetermined fixed phase advance angle.

A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine and configured to start the engine from an inactive state. A controller is programmed to execute a first control algorithm while output speed of the second electric machine is less than a first speed threshold. The controller is also programmed to execute a second control algorithm while output speed of the second electric machine is greater than the first speed threshold and less than a second speed threshold.

Disclosed is an engine starting control method for a flexible fuel vehicle (FFV) of supplying the heated fuel to the engine by heating an injector heater during cranking when it is determined that cranking condition and fuel heating condition are satisfied at the time of starting the vehicle having a starting auxiliary device for cranking the engine of FFV and a device for heating the fuel using the injector heater provided in an injector, wherein a pre-injection is auxiliary performed prior to a main injection during cold starting of the engine when the heating time of the injector heater exceeds a predetermined value, allowing stable starting with low fuel consumption at a time of cold starting an engine using ethanol fuel in winter.