Tune-Up Notes

NOTE: Always refer to Emission Control Label in engine compartment before attempting tune-up. If manual and label differ, always use emission label specifications.

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

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

If the Dura-Spark 2-piece distributor cap must be removed, first remove the top portion, then the rotor, then the bottom portion (adapter). When connecting a tachometer to the Dura-Spark ignition coil, install the tachometer alligator clip into the "DEC" (Tach Testing) cavity. If any spark plug wire is disconnected with this system, connection must first be greased with silicone grease before it is reattached.

Do not allow or create a condition of engine misfire in one or more cylinder for an extended period of time. Damage to catalytic converter may result due to loading converter with unburned air/fuel mixture.