* Engine speed: Timing advances at higher RPMs.
* Engine load: Timing changes based on throttle position and other load sensors.
* Engine temperature: Timing may be retarded (delayed) until the engine reaches operating temperature.
* Air/fuel ratio: The ECM uses information from oxygen sensors to optimize timing for efficient combustion.
Therefore, you cannot simply set a degree value for the timing. Any attempt to adjust the "timing" would involve adjusting the ECM's parameters, which usually requires specialized tools and knowledge. This is not a DIY task for someone without experience working on fuel-injected systems and using a diagnostic scan tool.
If you suspect a timing issue, the best approach is to:
1. Have the engine diagnosed by a qualified mechanic. They'll use a scan tool to check for diagnostic trouble codes (DTCs) and assess the ECM's control strategies.
2. Check for any vacuum leaks. These can significantly affect engine performance and timing.
3. Inspect the ignition system. Worn components like ignition wires, distributor cap (if applicable, though less likely on a 1987 2.3L EFI), and rotor can lead to misfires that might *seem* like a timing problem.
Trying to adjust the timing directly on this system without the proper equipment and understanding is likely to cause more damage.
