In timing control, 'initial spark timing' refers to the timing adjustments during start-up and open loop.

In timing control, 'initial spark timing' refers to the timing adjustments during start-up and open loop.

• A. The timing adjustments during start-up and open loop
• B. The rate of timing advance
• C. The total advance
• D. The boost retard

Answer: (A)

Baseline ignition timing is the timing setting the engine control system uses during start-up and when the engine is operating in open-loop, before any feedback from sensors is applied to adjust timing. This initial value provides a reliable, safe spark to start the engine and to run accurately when closed-loop control isn’t active. Once the engine moves out of start-up/open-loop, other timing adjustments come into play: the rate of timing advance describes how quickly the spark advances with RPM, and the total advance is the final spark angle after adding all contributions. Boost retard is a separate adjustment that can reduce timing under boost to prevent detonation. So this description directly captures the role of initial spark timing.

Baseline ignition timing is the timing setting the engine control system uses during start-up and when the engine is operating in open-loop, before any feedback from sensors is applied to adjust timing. This initial value provides a reliable, safe spark to start the engine and to run accurately when closed-loop control isn’t active. Once the engine moves out of start-up/open-loop, other timing adjustments come into play: the rate of timing advance describes how quickly the spark advances with RPM, and the total advance is the final spark angle after adding all contributions. Boost retard is a separate adjustment that can reduce timing under boost to prevent detonation. So this description directly captures the role of initial spark timing.