Late intake valve closing to improve cold startability for spark-ignition direct-injection (SIDI) engines

摘要

An engine control system includes a cam phaser that introduces a cam phase angle θ between a camshaft intake lobe and an associated crankshaft. An engine control module communicates with the cam phaser to introduce the cam phase angle θ while an engine is being started. The cam phase angle θ is selected such that the camshaft intake lobe opens an intake valve during at least a portion of a compression stroke of a cylinder that is associated with the camshaft intake lobe.