Abstract: The system is based on incorporating a start turbocompressor capable of injecting pressurized air in the inlet manifold of the motor. The turbocompressor is driven by air supplied by a storage reservoir and starts operating after an air starter motor has been actuated. Operation is continued until, as a result of the ignition of the fuel, the engine attains a high speed, after which the starter motor and the turbocompressor are disengaged, whereby the engine decelerates. When the engine reaches a preset low speed, the turbocompressor is reengaged and stages of operation of the turbocompressor coinciding with engine acceleration alternate with inoperative stages coinciding with engine deceleration until an engine speed above the low speed is maintained. An electronic sequencer controls the successive operations.