GM Buick/Oldsmobile/Pontiac/Full-Size 1975-1990 Repair Guide



The tune-up is a routine maintenance procedure which is essential for the efficient and economical operation of your vehicle's engine. Regular tune-ups will also help prolong the life of the engine.

The interval between tune-ups is a variable factor which depends upon the way you drive your vehicle, the conditions under which you drive it (city versus highway, weather, etc.), and the type of engine installed. A complete tune-up should be performed on your Buick, Olds or Pontiac at least every 15,000 miles or one year, whichever comes first. 1981-83 vehicles have an increased tune-up interval of 25,000 miles. On 1984 and later models, it is 30,000 miles.

This interval should be halved if the vehicle is operated under severe conditions such as trailer towing, prolonged idling (a common occurrence in the city), start and stop driving, or if starting and running problems are noticed. It is assumed here that the routine maintenance described in Routine Maintenance has been followed, as this goes hand-in-hand with the recommended tune-up procedures. The end result of a tune-up can only be the sum of all the various steps, so every step applicable to the tune-up should be followed.

If the specifications on the underhood sticker in the engine compartment of your vehicle disagree with the Tune-Up Specifications chart in this information, the figures on the sticker must be used. The sticker often reflects changes made during the production run, or displays specifications that apply only to your particular engine.

The replaceable parts involved in a tune-up include the spark plugs, air filter, distributor cap, rotor, and the spark plug wires. In addition to these parts and the adjustments involved in properly installing them, there are several adjustments of other parts involved in completing the job. These include carburetor idle speed and air/fuel mixture, ignition timing, and valve clearance adjustments.

This section gives specific procedures on how to tune-up your Buick, Pontiac or Oldsmobile, and is intended to be as complete and basic as possible.

When working with a running engine, make sure that there is proper ventilation. Also make sure that the transmission is in Neutral (unless otherwise specified) and the parking brake is fully applied. Always keep hands, clothing and tools well clear of the hot exhaust manifolds and radiator and especially the belts and fan. Remove any wrist or long neck jewelry or ties before beginning any job, and tuck long hair under a cap. When the engine is running, do not grasp ignition wires, distributor cap or coil wires as a shock in excess of 50,000 volts could result. Whenever working around the distributor, make sure the ignition is OFF.