How do you be SURE the fuel pump is bad on a 1987 G20 Chevy?

To determine if the fuel pump is bad on a 1987 Chevy G20, check for a lack of fuel pressure by using a fuel pressure gauge at the test port. Additionally, listen for a humming sound from the fuel tank when the ignition is turned on; if there's no sound, the pump may be faulty. Inspect the fuel pump relay and fuse for any issues, and look for signs of fuel leaks or damaged wiring. If these checks confirm no fuel delivery, the fuel pump likely needs replacement.