Fuel Pump Relay
WARNING: This page is about a different car, the 1994 Chevrolet Caprice and 1994 Buick Roadmaster. However, it is still accessible from the selected car via links, so may be relevant.
See MOTORS, RELAYS & SOLENOIDS in the apprpriate SYSTEM/COMPONENT TESTS - 5.7L article in the ENGINE PERFORMANCE section below.