OEM 2003 GMC Envoy Fuel Rail

2003 GMC Envoy Fuel Rail Parts Questions & Experts Answers

• Q: How to replace the fuel rail assembly on 2003 GMC Envoy?

  A: The first step to replace the Fuel Rail assembly requires bleeding the fuel system pressure. Use gm x-30a engine cleaner spray to clean the Cylinder Head and Fuel Rail assembly after which remove the Intake Manifold according to instructions on the package. Avoid soaking the Fuel Rail in cleaning solvent liquids while performing this task. The replacement process starts with severing the Fuel Pressure Regulator vacuum line along with fuel feed and return pipes (1, 2) from the Fuel Rail and then disconnecting the Fuel Injector harness in-line connector. First detach the Fuel Rail attaching bolts while paying attention to prevent damage to injector electrical connector terminals and spray tips to support the Fuel Rail during this operation. Insert proper caps and seal up drilled holes in order to secure the system from contamination. You must remove the twisted lower o-ring seal from each injector. Installation should begin when replacing the Fuel Rail is not part of the plan. Detach the fuel injectors together with the Fuel Pressure Regulator along with the Fuel Injector harness from the Fuel Rail for disassembly. The Fuel Injector harness needs to be installed on the Fuel Rail before adding the Fuel Pressure Regulator and subsequently the fuel injectors. Apply clean engine oil to new lower injector o-ring seals and install them onto each injector spray tip end. Secure the Fuel Rail assembly by using the attaching bolts since tightening them to 10 n.m (89 lb in) will be necessary. Route the fuel feed and return pipes (1, 2) through the Fuel Rail and to attach each electrical connector of the fuel injectors and the vacuum line for the Fuel Pressure Regulator. After installation of the Intake Manifold you must connect the negative Battery Cable. To check for leaks you must first switch on the ignition with the engine off for 2 seconds followed by turning it off for a period of 10 seconds before switching it on with the engine still off and conducting leak examinations on the fuel system.