Originally Posted by weasel56

A whine can be heard from the fuel pump at times when the fuel level is low, like when the light is on due to the lack of fluid around it to quiet it down. But not often. And often when the pump is going out it does lower its output, sometimes not noticeable at idle by gauge, but only when under load. What happens when the pressure is lower is that it will not atomize the fuel spray as well and it will run as if it were rich, yet be lean. If you have access to a fuel pressure tester and have any mechanical knowledge you can check it yourself pretty easily.