Testing Precautions
The following precautions MUST be observed during testing procedures:
- DO NOT ground tachometer terminal of distributor connector. Damage to the electronic module or ignition coil can result.
- Disconnect ignition switch connector at distributor before making compression checks.
- When using a timing light, connect at plug end of number 1 spark plug wire. DO NOT pierce plug boot.
- Remove spark plug wires, twist boot 1/2 turn and pull on boot (not on wire).
- Prior to diagnosis of HEI system, visually inspect spark plug wires, rotor contact button, plug wires boots, rotor and distributor cap for damage.
- If a tachometer is connected to the tachometer terminal, disconnect it before proceeding with the test.
- Check that wiring connector is properly attached to connector at side of distributor cap, and that spark plug leads are properly connected at both ends before continuing with test procedures.
- If engine is difficult to start or misses, check position of battery terminal connector at distributor cap. Terminal must be inserted on side of connector opposite hold-down clip.
- Intermittent no start condition may be caused by installation of a wrong pick-up coil or ignition coil.