Hybrid vehicle auto start systems and methods

A method of operating an engine control system includes reducing pressures within cylinders of an engine based on an auto start command signal including: receiving a torque request signal; calculating a powertrain output torque; and controlling air flow to the engine based on the powertrain output torque. During a startup of the engine: electric motor torque is increased to a predetermined level and reduced to increase a current speed of the engine; combustion torque of the engine is activated and increased after the current speed is within a predetermined range and a manifold absolute pressure is less than a predetermined level; and the electric motor torque is increased based on a crankshaft output torque signal to increase a crankshaft output torque subsequent to the reducing of the electric motor torque and while performing the activating of the combustion torque.