GM Metro/Sprint 1985-1993 Repair Guide



See Figures 1 and 2

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Fig. Fig. 1: Vehicle emission control information label

In order to extract the full measure of performance and economy from your engine it is essential that it is properly tuned at regular intervals. A regular tune-up will keep your truck's engine running smoothly and will prevent the annoying breakdowns and poor performance associated with an untuned engine.

A complete tune-up should be performed every 30,000 miles. This interval should be halved if the vehicle is operated under severe conditions such as prolonged idling, start-and-stop driving, or if starting or running problems are noticed. It is assumed that the routine maintenance described in Routine Maintenance has been kept up, as this will have a decided effect on the results of a tune-up. All of the applicable steps of a tune-up should be followed in order, as the result is a cumulative one.

If the specifications on the underhood tune-up sticker in the engine compartment disagree with the Tune-Up Specifications chart in this Section, the figures on the sticker must be used. The sticker often reflects changes made during the production run.

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Fig. Fig. 2: Gasoline Engine Tune-Up Specifications