The term “tune-up” dates to the time when Henry Ford was working on his first automobile prototype. In Ford’s simple ignition system, there was one ignition coil for each spark plug. If there were four spark plugs, there were four ignition coils, which needed to be adjusted to provide the same spark intensity for better idle and acceleration. As these ignition coils worked, they made a buzzing sound, and when they were adjusted properly, they all buzzed in “tune.” The term “tune-up” stuck and became associated with replacing spark plugs and correcting rough idle problems affecting engine performance.
Once the distributor was developed, the term “tune-up” had no meaning, but the consumer who was used to hearing this term around a garage still associated poor running quality with the need for a “tune-up.”
Today’s automobiles do not require “tune-ups.” The term indicates the need for routine maintenance and should not be associated with poor performance. Automobile manufacturers have developed recommended routine maintenance schedules, which specify intervals for replacing spark plugs, PCV valves, fuel filters, etc. These schedules also specify intervals for checking or adjusting ignition timing, idle speed and other items related to engine operations, as well as emission control related devices.