If you replace the stock camshaft with a high performance camshaft, you should adjust the target idle speed.

If you replace the stock camshaft with a high performance camshaft, you should adjust the target idle speed.

• A. Adjust The Target Idle Speed
• B. Change Spark Timing
• C. Retune Fuel Injectors
• D. Replace Sensor Types

Answer: (A)

A high-performance camshaft changes how the engine breathes at idle, which alters the amount of air the engine needs to idle smoothly. The longer duration and potential valve overlap of a hotter cam affect idle vacuum and airflow, so the idle control system must be told a different target RPM to compensate. By adjusting the target idle speed, you align the engine’s idle stability with the new breathing characteristics, keeping idle smooth and predictable. Other adjustments like spark timing or fuel injector calibration may come into play later for overall performance, but the direct step to accommodate the cam swap is updating the idle speed target.

A high-performance camshaft changes how the engine breathes at idle, which alters the amount of air the engine needs to idle smoothly. The longer duration and potential valve overlap of a hotter cam affect idle vacuum and airflow, so the idle control system must be told a different target RPM to compensate. By adjusting the target idle speed, you align the engine’s idle stability with the new breathing characteristics, keeping idle smooth and predictable. Other adjustments like spark timing or fuel injector calibration may come into play later for overall performance, but the direct step to accommodate the cam swap is updating the idle speed target.