Ignition MAP

Basic Ignition Timing Map:

Basic Ignition Timing Map

The basic ignition timing map is calculated on two conditions, these are:
- Engine speed
- Intake manifold pressure

The above ignition map illustrates that ignition timing advances as engine speed increases. However, as intake manifold pressure (engine load) increases the amount of ignition advance will decrease, to prevent detonation.

Corrections are made to this basic ignition map under the following conditions:
- Engine coolant temperature below 5°C (40°F) and manifold pressure below 1.0 bar.
- Manifold pressure above 1.0 bar.
- Ignition knock occurring
- Engine deceleration