Tune-Up Notes

NOTE: When performing tune-up procedures described in this article, the following notes and precautions must be followed:

In some applications within this article it will be necessary to refer to the engine calibration number. Most numbers for V8 engines are located on an identification label on front of right valve cover.

For Tune-Up purposes, "Light Duty" refers to vehicles up to 8500 lbs. GVW. "Heavy Duty" refers to vehicles exceeding 8500 lbs. GVW.

When connecting a tachometer to SSI coil, install the alligator clip on tachometer into the "DEC" (TACH TEST) cavity. For other items affecting Tune-Up, see FUEL SYSTEMS section or EMISSIONS section.

Due to production changes, always refer to Engine Tune-Up Decal in engine compartment before attempting tune-up. In the event of a conflict between specifications given in this manual and decal specifications, use the decal specifications.

When performing tune-up on vehicles equipped with a catalytic converter, do not allow or create a condition of engine misfire in one or more cylinders for an extended period of time. Damage to converter from overheating may occur due to loading with unburned fuel.