To improve power performance while avoiding or suppressing surging, an engine control device comprises a VVT mechanism for varying the open/close timing of an intake valve, and the occurrence of surging is determined by comparing an engine rotation variation width with a surge determination threshold. When it is determined that surging has occurred, an ignition timing surge correction amount is set at a value that has been corrected in an advancement direction, and the ignition timing is correct...

A spark plug circuit for, and a method of, reducing or preventing the corrosion of a spark plug electrodes in an internal combustion engine. The circuit and method provide a positive voltage across the center electrode/ground electrode gap, which repels positively charged corrosion mechanisms, such as calcium and phosphorus ions.

An angular interval between a piston top dead center of one of two cylinders of an engine and a piston top dead center of the other one of the two cylinders is not a quotient of 360.degree. CA divided by an integer number. A timing rotor is rotated synchronously with a crankshaft of the engine and includes a plurality of teeth that are arranged at equal intervals, each of which is set as a predetermined quotient of the angular interval divided by a corresponding integer number.

An extender for connecting a high voltage source to a spark plug has a conductive rod with one end suitable for electrical connection to the high voltage source and a second end suitable for electrical connection to the spark plug, and a sleeve injection-molded over the conductive rod so as to be in void-free relation with an exterior surface of the conductive rod. The conductive rod has a first end extending outwardly therefrom. The sleeve defines a spark plug-receiving receptacle at the second...

To reduce the cost of an ignition plug tube by making it of a cylindrical member and to provide a simple structure having only a small number of parts for mounting the ignition plug tube. A mounting structure of an ignition plug tube that is made of a cylindrical member includes a sealing member made of a soft member fitted to a cylinder head cover. The sealing member is interposed between the cylinder head cover and the ignition plug tube. The ignition plug tube is fixed and supported between a...

An internal combustion engine 10 has a cylinder head 11 slideably supporting one or more poppet valves 30. At least one of the poppet valves 30 in each combustion chamber of the engine 10 has a primary electrode 69, 269a, 269b, 369a, 369b connected thereto so as to be electrically insulated from the cylinder head 11. The primary electrode 69, 269a, 269b, 369a, 369b forms in combination with one or more secondary electrodes 33, 133, 233, 333, 433, 533 one or more electrode pairs between each of w...

An ignition coil apparatus for an internal combustion engine with a cylinder having first and second spark plugs can reliably detect an ionic current without discharging a bias voltage even at the start of supplying a primary current. The apparatus includes a coil member with primary and secondary coils. The secondary coil has first and second ends connected to the spark plugs through high voltage output terminals, respectively. A first diode has its anode connected to a capacitor, and its catho...

In a knock sensor signal processing apparatus, a first apparatus which receives an engine knock sensor signal performs A/D conversions of the signal with a predetermined period and transmits successive pluralities of A/D values in parallel, by serial data communication, to a second apparatus in response to respective commands received from the second apparatus. The number of communication lines provided for transmitting the A/D values is made greater than those for transmitting commands from the...

A capacitor discharge ignition device in which a coil unit including an ignition coil and an exciter coil wound around a common core, and an ignition unit including a circuit board and components of an ignition circuit mounted to the circuit board are housed in a case and molded with resin poured into the case, wherein the ignition coil and the exciter coil are placed axially with a spacing therebetween and a space is formed between the coils, the circuit board of the ignition unit is placed on ...

A multi-spark ignition system for an internal combustion engine includes ignition coils each of which is mounted on one of spark plugs of an engine, an energy storing circuit, switching elements that repeatedly discharge electric energy stored by the energy storing circuit into the primary coil of the ignition coils; and a control circuit that controls the energy storing circuit and the switching elements according to consolidated signals each of which includes an energy storing command signal f...