Engine Tune-Up

Regular tune-ups help maintain vehicle safety and performance
by making sure that faulty parts are replaced promptly.


Often part of a large 30,000/60,000/90,000 mile service that includes inspections, and fluid and filter changes. These services are part of the manufacturer’s recommended scheduled maintenance detailed in the owner’s manual.

The traditional term “tune-up” has changed over the years. Before electronics came into the picture, the term “tune-up” was used for the maintenance part of replacing the spark plugs, distributor points, inspecting or replacing the cap and rotor and possibly the air and fuel filters.  Going from replacing parts to bring the ignition and fuel systems up to specs for maximum performance and efficiency to computers that control engines of today by adjusting the air-fuel mixture and spark timing to compensate for wear like when the electrodes and spark plugs are worn down.

Today’s service technicians will inspect and possibly test the fuel, ignition and emissions systems to look for faulty vacuum hoses, oxygen sensors and other parts that can hurt performance.

Having your vehicle serviced and inspected periodically is a good way to extend its life and keep it operating efficiently.

Mechanically Timed Ignition

Some four-stroke engines (used mostly before 1974) use a mechanically timed electrical ignition system.  The heart of the system is the distributor, which contains a rotating cam driven by the engine that drives a set of breaker points, a condenser, a rotor and a distributor cap.

Tune up 1

External to the distributor is the ignition coil, the spark plugs and wires linking the distributor to the spark plugs.  A lead-acid battery powers the system.







Electronic Ignition

The disadvantage of the mechanical system is the use of breaker points that are subject to wear.

Electronic ignition  solves these problems. The breaker points were replaced by a sensor,  which responds to a rotating magnet mounted on the distributor shaft. The sensor output is then used to trigger a switching device, which switches a large current through the coil.

Tune up 2Other innovations are currently available on various cars. In some models, rather than one central coil, there are individual coils on each spark plug, sometimes known as direct ignition or coil on plug (COP).  This allows the coil a longer time to accumulate a charge between sparks, and therefore a higher energy spark, resulting in better performance and fuel efficiency.