You must consult your vehicle's owner's manual or a reputable AMC repair manual specific to that year and engine. These manuals will provide the proper specifications, often including different settings based on engine temperature and operating conditions.
Generally, the timing will be in the range of 0 to 10 degrees BTDC (Before Top Dead Center) at idle. However, this is just a broad estimate. The actual setting will be significantly affected by:
* Vacuum Advance: This mechanism adds timing as engine load decreases (higher vacuum). The advance curve is critical and is controlled by the distributor diaphragm.
* Centrifugal Advance: This mechanism adds timing as engine RPM increases. This is mechanical and integrated into the distributor.
* Engine condition: Worn components (e.g., distributor, vacuum lines, ignition components) will affect the optimal timing.
To find the correct timing:
1. Consult your owner's manual or a repair manual: This is the most reliable source of information.
2. Check for markings on the distributor: There may be markings indicating the initial timing setting.
3. Use a timing light: With the engine running, a timing light will allow you to see the timing marks on the harmonic balancer and adjust the distributor accordingly. The procedure for this is detailed in repair manuals.
Improper timing can lead to poor performance, reduced fuel economy, and potential engine damage. If you are unsure, consult a qualified mechanic experienced with AMC engines. Attempting to adjust the timing without proper knowledge and tools can be risky.
