Fuel System Pressure Release
WARNING: This page is about a different car, the 2003 GMC Savana and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Remove fuel tank cap and release fuel system pressure before servicing any fuel injection related components. After releasing fuel system pressure, a small amount of fuel may be released when servicing fuel lines, fuel pump or fuel connections. Cover fuel system components with a shop towel before disconnection. DO NOT allow fuel to contact engine or electrical components.
CAUTION:
Fuel system is under pressure. Pressure must be released prior to servicing fuel system.
Disconnect negative battery terminal. Loosen fuel filler cap to relieve fuel tank vapor pressure. Connect Fuel Pressure Gauge (J-34730-1A) to fuel pressure test port. Wrap a shop towel around fitting while connecting gauge to avoid spillage. Install gauge bleed hose into an approved gasoline container. Open valve on gauge to bleed system pressure. Fuel connections are now safe for servicing. Drain any fuel remaining in gauge into an approved gasoline container.