BMW Spark Plug Wire Set - STI 12121307171

Product Information

A spark plug wire set is a main component in the ignition system of older gasoline vehicles that use a distributor. The primary function of spark plug wires is to transmit the high-voltage electricity generated by the ignition coil to the spark plugs. The wires are designed to handle very high voltage without too much resistance or causing electrical interference to other systems. A good quality set of spark plug wires ensures efficient combustion, optimal engine performance, and smooth vehicle operation.

Four main components make up a spark plug wire set: The conductive cable itself, which is often a spiral wound wire around a core material to help abate interference and improve durability, the insulation layer, the spark plug boots, and the connectors. Depending on the application, some spark plug wire sets may or may not include the ignition coil wire that goes between the ignition coil and distributor, so be sure to check before ordering.

When a spark plug wire set is worn out or in need of replacement, the engine will struggle to run at peak efficiency, misfire, and in some conditions may not allow the engine to run at all. Depending on climate and how often the vehicle is driven, a quality spark plug wire set will last between 30-50k miles.

• Misfires or hesitation: Rough idling, hesitation, loss of power, and occasional misfires are signs of failing spark plug wires.
• Visible Damage: Spark plug wire sets should appear clean, un-faded, with shiny connectors and malleable boots. If a spark plug wire is cracked or faded, especially around high-heat areas, it should be replaced
• Loose connections: Check both connections to make sure the metal contacts are clean and positively engaging with the distributor and the spark plugs. The boots should confidently snap onto the spark plugs.
• Increased resistance: You can test a spark plug wire for increased resistance, although due to different constructions and different resistance numbers, this can be more difficult than just replacing a spark plug wire set that is suspect or old. Carbon core resistor wires will be in the range of 4-10k ohms per foot, while spiral wound core wires will be between 50 and 500 ohms per foot, and standard copper core wires will be less than 50 ohms per foot.

About STI

STI is a division of the Karlyn Industries Corporation. Founded in 1971, Karlyn Industries is a family owned business that was started by Mr. Hans Bierdumpfel. Hans was born and trained in Germany as an Engineer and emigrated to the U.S. in 1949. He held leading Engineering positions with such esteemed companies as Sonotone Corporation, formerly of Elmsford/Cold Springs, N.Y. and Wells Manufacturing, of Northvale N.J. before founding Karlyn Industries 33 years ago. The company started producing the first U.S. made VW Beetle Ball Joints and Tie Rod Ends, in Mount Vernon, N.Y. As a domestic manufacturer of Volkswagen suspension items, Karlyn created a customer base here in the United States that has been loyal for over thirty years. Today, Karlyn Industries has branched out into suspension items for Audi, BMW, Mercedes Benz, Volvo, Saab and Honda. Karlyn Industries is also responsible for a high performance line of spark plug ignition cable sets with a reputation for quality. The biggest difference between Karlyn Industries and other manufacturers is their willingness to use a manual assembly process when it proves to deliver a superior product over automated production.