Abstract: According to the NVH development process, under the air conditioner in idle condition, idle noise pressure level is high and the sound quality is poor. Diagnosis test indicates that the car idle noise is too large because the pump generates vibration and noise and they are transferred to the body. To reduce the vibration and noise of the fuel pump, the fuel pump steering gear and the oil plate were optimized. With such modifications, the test car reduces its interior noise by 4.9dB(A) in idling. At the same time, the subjective evaluation of the car comfort is significantly improved.