Abstract: A spark plug for internal combustion engines includes a third electrode in addition to a center electrode and a ground electrode which define a normal or main spark gap. Defined between the center electrode and the third electrode is an auxiliary gap adjoining the normal gap and adapted to produce a capacitive discharge at a voltage lower than that of the normal gap, and a discharge is induced across the normal gap by the capacitive discharge across the auxiliary gap.

Abstract: An internal combustion engine includes an intake system and an exhaaust system, and an exhaust gas recirculation conduit leads from the exhaust system to the intake system for recirculating exhaust gas. An exhaust gas recirculation control valve at an intermediate part of the exhaust gas recirculation passage controls the flow of exhaust gases therein, and is operated by supply of actuating vacuum. The supply of actuating vacuum to the exhaust gas recirculation control valve is furnished according to engine operational conditions. A vacuum tank accumulates vacuum while the engine is running. A vacuum conduit joins the vacuum tank to the exhaust gas recirculation control valve, and is controlled by a vacuum valve which is closed when the ignition system of the engine is being supplied with electrical power, and is open when the ignition system is not being supplied with electrical power.

Abstract: A fuel vaporization promoting device comprises a heater vessel arranged in the collecting portion of the intake manifold of an engine. The heater vessel contains therein at least one PTC element and is shaped in the form of a flat plate. The heater element is spaced above the bottom wall of the collecting portion by a support member having a small cross-sectional area so that an air gap is formed between the lower face of the heater vessel and the bottom wall of the collecting portion. The heater vessel is actuated after the engine is operating under its own power and is turned off when the warm-up of the engine is completed.

Abstract: An electronic fuel injection system for an internal combustion engine, whereby fuel is introduced into the engine under controlled pressure through electro-magnetic valves at a flow rate controlled in accordance with the opening duration of the electro-magnetic valves. A fuel damper is provided in the fuel line upstream of all the electro-magnetic valves for leveling the pulsation of fuel pressure.