A method and system for a variable displacement engine

摘要

A strategy and control system for a variable displacement engine in which cylinder deactivation is obtained by intake cam phasing and exhaust valve deactivation. Fuel control for the engine and spark deactivation are sequenced with valve deactivation to avoid transferring engine exhaust gases to the intake manifold of the engine during a transition between full cylinder operation and partial cylinder operation. Excess air flow through the exhaust system for the engine is avoided during a transition from partial cylinder operation to full cylinder operation. These features achieve stable engine performance during the transition.