Table of contents: Depressurisation 🠇 Pressurising 🠇
Note: Refer to the warning note in Section 1 before proceeding.
Depressurisation
Warning: The following procedure will merely relieve the pressure in the fuel system - remember that fuel will still be present in the system components and take precautions accordingly before disconnecting any of them.
1. The fuel system referred to in this Section is defined as the tank-mounted fuel pump, the fuel filter, the fuel injectors, the fuel rail, the pressure regulator and the pipes of the fuel lines between these components. All these contain fuel which will be under pressure while the engine is running, and/or while the ignition is switched on. The pressure will remain for some time after the ignition has been switched off, and must be relieved in a controlled fashion when any of these components are disturbed for servicing work.
2. Disconnect the battery negative terminal (refer to "Disconnecting the battery").
3. Some models are equipped with a pressure relief valve on the fuel rail. On these models, unscrew the cap from the valve and position a container beneath the valve. Hold a wad of rag over the valve and relieve the pressure in the system by depressing the valve core with a suitable screwdriver. Be prepared for the squirt of fuel as the valve core is depressed and catch it with the rag. Hold the valve core down until no more fuel is expelled from the valve. Once the pressure is relieved, securely refit the valve cap.
4. Where no valve is fitted to the fuel rail, it will be necessary to release the pressure as the fuel pipe is disconnected. Place a container beneath the union and position a large rag around the union to catch any fuel spray which may be expelled. Slowly release and disconnect the fuel pipe and catch any spilt fuel in the container. Plug the pipe/union to minimise fuel loss and prevent the entry of dirt into the fuel system.
Pressurising
5. After any work is carried out on the fuel system, the system should be pressurised as follows.
6. Depress the accelerator pedal fully then switch on the ignition. Hold the pedal depressed for approximately 1 second then release it. The ECU should then operate the fuel pump for between 20 and 30 seconds to refill the fuel system. Once the fuel pump stops the ignition can be switched off.