A control system for an engine of an automotive vehicle equipped with a lock-up type automatic transmission.The engine control system comprises a gear ratio determinating circuit and a vehicle speed detector for determining whether the automotive vehicle is operating in a predetermined lock-up range or not and a logic circuit for generating a lock-up signal that indicates that the automotive vehicle is operating within said predetermined lock-up range, whereupon exhaust gas recirculation and ignition timing are varied from their ordinary patterns to a pattern suitable for operation of the engine with the torque converter operating in a lock-up state.