How to Tune Up a Car

by TJ Hinton

The term “tuneup” originally referred to a set of procedures to inspect and adjust certain components within the ignition system. Typically, these would include inspecting the spark plugs and replacing them or adjusting the gaps as necessary, as well as checking out the spark plug wires for damage. You would also inspect the rotor button and contacts within the distributor cap for burning and wear, and replace the cap as needed. Using a points file, you would touch up the point contacts, remove any transferred metal, lubricate the cam follower and adjust the points. Then you would start the engine and perform the dynamic or advanced timing procedure according to your vehicle manufacturer's specifications. You might need to adjust the idle speed after setting the timing, but generally you wouldn't need to adjust the carburetor further.

Modern Interpretation

Late-model engines don't use most of the components in the original procedure. However, the term has evolved along with the engines to include current technology. The spark plug and spark plug wire checks are still valid, along with the distributor, or ignition module terminal checks. Frequently, procedures such as fuel injector and intake component cleaning, air-filter replacement and PCV valve inspection fall under the “tuneup” umbrella, along with scans and tests designed to check the various sensors that supply the PCM with performance-related data.

About the Author

TJ Hinton trained as an auto mechanic at Mississippi Gulf Coast Community College and then later graduated from MMI as a certified motorcycle mechanic . He's also worked for 20+ years in home construction, remodeling and repair. His articles appear on and

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