The following should be scaled down at the same rate as airflow:

The following should be scaled down at the same rate as airflow:

• A. Engine Load
• B. High Boost
• C. Fuel Injector Size
• D. Spark Timing

Answer: (C)

Maintaining the right air-fuel balance means fuel delivery must track how much air the engine is moving. When airflow goes up, you need more fuel, and when it drops, you need less. The component that directly controls how much fuel can be delivered per engine cycle is the fuel injector, whose capacity (injector size) sets the maximum fuel flow at a given pressure. If injector size is matched to the range of expected airflow, the engine can supply just the right amount of fuel across operating conditions by adjusting the injector pulse width to achieve the target air-fuel ratio. The other items describe conditions or timing adjustments that influence how the engine runs, but they don’t fix how much fuel can be delivered in response to changing air, so they aren’t the element that should scale with airflow in the same direct way.

Maintaining the right air-fuel balance means fuel delivery must track how much air the engine is moving. When airflow goes up, you need more fuel, and when it drops, you need less. The component that directly controls how much fuel can be delivered per engine cycle is the fuel injector, whose capacity (injector size) sets the maximum fuel flow at a given pressure. If injector size is matched to the range of expected airflow, the engine can supply just the right amount of fuel across operating conditions by adjusting the injector pulse width to achieve the target air-fuel ratio. The other items describe conditions or timing adjustments that influence how the engine runs, but they don’t fix how much fuel can be delivered in response to changing air, so they aren’t the element that should scale with airflow in the same direct way.