In order to extract the full measure of performance and economy from your car's engine it is essential that it be properly tuned at regular intervals. A regularly scheduled tune-up will keep your car's engine running smoothly and will prevent the annoying minor breakdowns and poor performance associated with an untuned engine.
A complete tune-up should be performed at the interval specified in the "Maintenance Intervals" chart in . This interval should be halved if the car is operated under severe conditions, such as trailer towing, prolonged idling, continual stop-and-start driving, or if starting and running problems are noticed. It is assumed that the routine maintenance described in the first section has been kept up, as this will have a decided effect on the results of a tune-up. All of the applicable steps should be followed in order, as the result is a cumulative one.
If the specifications on the tune-up label in the engine compartment of your X-Body disagree with the "Tune-Up Specifications" chart in this guide, the figures on the sticker must be used. The label often reflects changes made during the production run.