Which statement about peak and hold injectors is true?

Which statement about peak and hold injectors is true?

• A. They are low resistance injectors
• B. They are high impedance
• C. They are controlled by MAP
• D. They are used in diesel engines

Answer: (A)

Peak and hold injectors are defined by their low electrical resistance, which lets a large surge of current flow when they first energize. That quick, high current opens the injector rapidly, and then the current is reduced to a lower holding level to keep it open with less power. This driving pattern relies on the injector coil being low resistance so the supply can deliver that strong opening pulse and then taper off. High-impedance injectors wouldn’t allow that same short, strong opening burst, so they aren’t described as peak and hold. While the engine management system uses sensor data like MAP to compute fueling, MAP itself isn’t what makes an injector peak-and-hold; it’s about how the injector is driven electrically. Diesel engines rely on different injection systems and aren’t characterized by peak-and-hold injectors in the same way gasoline engines are. So the statement that fits best is that these injectors are low resistance.

Peak and hold injectors are defined by their low electrical resistance, which lets a large surge of current flow when they first energize. That quick, high current opens the injector rapidly, and then the current is reduced to a lower holding level to keep it open with less power. This driving pattern relies on the injector coil being low resistance so the supply can deliver that strong opening pulse and then taper off. High-impedance injectors wouldn’t allow that same short, strong opening burst, so they aren’t described as peak and hold. While the engine management system uses sensor data like MAP to compute fueling, MAP itself isn’t what makes an injector peak-and-hold; it’s about how the injector is driven electrically. Diesel engines rely on different injection systems and aren’t characterized by peak-and-hold injectors in the same way gasoline engines are. So the statement that fits best is that these injectors are low resistance.