If your fuel pump stops working (no noise, no line pressure), the first thing that should be checked is the pump's voltage supply and electrical connections. An open relay, blown fuse or loose wire may be all that's preventing the pump from working. Low battery voltage can also reduce the pump's ability to generate pressure by reducing the speed of the pump motor.

Measuring static output pressure and fuel delivery are the two standard diagnostic tests that can be used to determine a pump's ability to deliver fuel.

Static pressure is measured with a gauge attached to the fuel rail or teed into the fuel supply line with the engine off and pump energized. Fuel flow is measured by disconnecting the fuel supply line, energizing the pump for a specified number of seconds (engine off) and measuring the volume of fuel delivered into a container.

If static pressure or the volume of fuel delivered is less than your car manufacturer's specifications, your fuel pump needs to be replaced. Replacement would also be required if the pump's check valve has failed (inability to hold residual pressure in the system after the ignition is turned off).