A method for controlling a throttle loss recovery system for a spark-ignition internal combustion engine wherein the TLR system includes a turbine through which intake air passes before being delivered to the engine and an electrical generator coupled to the turbine and driven to rotate by the turbine, the TLR system further including a bypass passage for bypassing the turbine and a bypass valve controllable to regulate flow through the bypass passage, and wherein the turbine comprises a high-leakage variable-nozzle turbine that is controllable between fully closed and fully open positions, flow rate through the VNT at the fully closed position being greater than a required engine idle air flow rate, the TLR system further including a throttle valve in series with the VNT for regulating flow to the engine, the method comprising the steps of: detecting a rotational speed ω of the generator; providing a rectifier, a filter, an over-voltage controller, and a pulse width modulation controller between the generator and a load served by the generator such that AC electrical power generated by the generator is rectified and filtered into DC current, over-voltage controlled, and is supplied to the load via the PWM controller; predefining an electrical power generation zone bounded on one side by a predefined minimum generator speed threshold ω min and on an opposite side by a predefined maximum generator speed threshold ω max; configuring the PWM controller such that when the TLR system is activated a duty cycle of the PWM controller is equal to: zero when generator speed ω is less than ω min; 100% when ω is greater than ω max; and F when ω is within the electrical power generation zone, where F is greater than zero but less than 100%; at engine idle, controlling engine air flow rate by setting the VNT at the fully closed position, setting the bypass valve at a partially open position, and controlling the throttle valve to achieve the required idle air flow rate. detecting a rotational speed ω of the generator; providing a rectifier, a filter, an over-voltage controller, and a pulse width modulation controller between the generator and a load served by the generator such that AC electrical power generated by the generator is rectified and filtered into DC current, over-voltage controlled, and is supplied to the load via the PWM controller; predefining an electrical power generation zone bounded on one side by a predefined minimum generator speed threshold ω min and on an opposite side by a predefined maximum generator speed threshold ω max; configuring the PWM controller such that when the TLR system is activated a duty cycle of the PWM controller is equal to: zero when generator speed ω is less than ω min; 100% when ω is greater than ω max; and F when ω is within the electrical power generation zone, where F is greater than zero but less than 100%; zero when generator speed ω is less than ω min; 100% when ω is greater than ω max; and F when ω is within the electrical power generation zone, where F is greater than zero but less than 100%; at engine idle, controlling engine air flow rate by setting the VNT at the fully closed position, setting the bypass valve at a partially open position, and controlling the throttle valve to achieve the required idle air flow rate.