Does a faulty alternator affect acceleration?

Yes, a faulty alternator can absolutely affect vehicle acceleration.

When the alternator fails, it cannot supply enough electrical power to the engine’s electronic systems. The vehicle has to rely entirely on the car battery for power. Weak electrical output can disrupt the engine control unit, fuel injection system, ignition system, and sensors. This leads to delayed throttle response, sluggish acceleration, engine hesitation, and even power loss when driving.

In severe cases, low voltage from a bad alternator may also cause the engine to misfire or stall, making acceleration even worse.