GM Metro/Sprint 1985-1993 Repair Guide

Service Precautions


When connecting the tachometer in the following procedures, be sure not to ground the tachometer terminal. Grounding the tachometer could result in damage to the igniter or ignition coil.

Be sure that the tachometer being used is compatible with the ignition system before installation. Incompatible equipment installation could cause damage to the ignition system.

Before setting timing, make sure the headlights, heater fan, engine cooling fan and any other electrical equipment is turned off. If any current drawing systems are operating, the idle up system, if equipped, will operate and cause the idle speed to be higher than normal.