Controlling spark of an engine with adjustable intake valve timing

A system and method to control spark timing of an engine wherein the injection timing of the engine is varied relative to a crankshaft position depending on engine operating conditions. According to the method, spark timing is varied as fuel injection timing varies for at least a portion of the engine operating range. The method can reduce fuel consumption, reduce transient fuel requirements, improve engine performance, and reduce CO emissions, at least under some conditions.