The fuel systems operate under high fuel pressures. It is very important that the pressure be properly relieved prior to servicing the system or any of its components.
Before servicing the vehicle, refer to the Precautions section.
WARNINGDo not perform this procedure for more than 2 minutes to avoid damaging the catalytic converter.
- Loosen the fuel filler cap to release the fuel tank pressure.
- Remove the fuel pump relay from the junction block.
- Crank the engine, allowing it to start and stall.
- Crank the engine for an additional 3 seconds to relieve any remaining fuel pressure.
- Disconnect the negative battery cable to avoid repressurizing the fuel system.
- Install the fuel pump relay in the junction block.
- Tighten the fuel filler cap.
- After you are finished working on the fuel system, connect the negative battery cable.
5.3L & 6.0L Engines
- Disconnect the negative battery cable.
- Install Fuel Pressure Gauge J 34730-1A or equivalent to the fuel pressure connection.
- Loosen the fuel fill cap to relieve the fuel tank vapor pressure.
- Open the valve on the fuel pressure gauge to bleed the system pressure. The fuel connections are now safe for servicing. Drain any fuel remaining in the gauge into an approved container. Once the system pressure is completely relieved, remove the fuel pressure gauge.