The fuel pump should run for 2 seconds when the key is turned on then shut off. when the engine is running, the fuel pump should run constantly. if it doesn't, the engine will stall immediately. If you replaced the pump and did not put any gas in the tank, but cycled the pump to see if it works, then it will be noisy. It should make a very faint hum with fuel in the tank. if it is noisy with fuel in the tank, then the pump you bought is bad. New parts arent always good parts.