During start-to-idle progression, what indicates readiness to transition to idle?

• A. Start, then hold at max rpm.
• B. Transition to idle and monitor for stability.
• C. Open all fuel valves.
• D. Shut down after light-off.

Answer: (B)

The key idea is that you only move into idle when the engine is in a stable, self-sustaining state at the idle speed. Readiness to transition means the rpm has reached the idle setpoint and stays there, with all critical parameters within limits—a steady oil pressure, stable exhaust temperature, and no abnormal vibrations or surge. Once that stability is confirmed, you transition to idle and continue to monitor for any signs of instability.

Holding at maximum rpm isn’t appropriate because it doesn’t indicate the engine has settled into a safe idle speed. Opening all fuel valves isn’t a readiness signal and could lead to uncontrolled fuel flow and instability. Shutting down after light-off defeats the purpose of the start-to-idle sequence.