Fuel Pump Noise

Hey there. Im lookin at a 91 mustang (4 cylinder), automatic transmission, rear wheel drive, with 206 km's on it. it looks fine, except for one problem that concerns me. when the car was started, there seemed to be a sort of squeeling/humming noise coming from the rear of the car. I instantly recognised this sound as coming from the fuel pump, and asked the seller about it. He replied by saying that the guys at the local Ford dealership claimed that this was a problem with all 91, 4 banger Mustangs and that the fuel pump is still in good shape. Is this true or am I being played for a fool?