Ignition Timing: Adjustments

Timing specifications for each engine are listed on the Vehicle Emissions Control Information label on the radiator cover. When using a timing light, connect an adapter between the No. 1 spark plug and the No. 1 spark plug wire, or use an inductive type pick-up. Do not pierce the plug lead. Once the insulation of the spark plug cable has been broken, voltage may arc to the nearest ground, the spark plug will not fire properly. Always follow the tune-up label procedures when adjusting timing.

Figure 1- Magnetic Timing Probe Hole:

Both engines incorporate a magnetic timing probe hole for use with special electronic timing equipment. Figure 1 shows a typical magnetic probe hole. Consult manufacturer's instructions for use of this equipment.

Set Ignition Timing

Figure 8- ALDL Connector- Set Timing:

The ignition timing marks are located on the engine front cover. A slot on the balancer indicates engine top dead center. Refer to the label located in the engine compartment. Follow all instructions on the label.
1. With engine RUNNING at operating temperature, choke fully open and air conditioning OFF, ground the diagnostic terminal of the ALDL terminal, Figure 8.
2. With the use of a timing light or meter, set timing at specified rpm by loosening the distributor clamp bolt and rotating the distributor until specified timing is obtained.
3. Tighten the distributor clamp bolt and recheck timing to make sure the distributor was not moved during tightening.
4. With the engine still running, unground the diagnostic terminal.
5. Make carburetor adjustments as required.