Car beeping sound when hit gas?

-my car is an infiniti qx4 1997 . some time it have a sound like a running fan .. the more i hit the gas the sound get loader ...but i stop after 5-10min .sometime the sound come back...and another question is .. ( i go to the body shop . they check the electric wire and not enough power to go thru ..

and how 铆m fix it ? thank sproblem could be the electric fuel pump that is in the tank..