Note. Before starting work, read the warning given in paragraph 1.
Pressure relief
Attention! The following procedure will only depressurize the fuel system, but remember that there is still fuel in the system and be careful when disconnecting any of them.
1. The fuel system referred to in this paragraph includes a tank-mounted fuel pump, a fuel filter, fuel injectors, a fuel rail, and pipes and hoses connecting these elements. All contain fuel which will be pressurized when the engine is running and/or the ignition is on. The pressure remains for some time after the ignition is switched off and must be released in a controlled manner before working on any of the above elements.
2. Disconnect the ground wire from the battery (see «Disconnecting the battery»).
3. Some models are equipped with a safety valve located on the fuel rail (pic. 7.3). On these models, unscrew the cap on the valve and place a suitable container under the valve. Wrap a rag around the valve and depressurize the system by pushing the valve stem with a suitable screwdriver. Be prepared for fuel to flow out when you press the spool; keep a rag ready. Hold the spool until fuel flow from the valve stops. After relieving pressure, screw the cap securely onto the valve.
Pic. 7.3. Fuel Rail Relief Valve (marked with an arrow) (1.6L model shown)
4. If there is no valve on the fuel rail, the fuel line must be disconnected to relieve pressure. Place a suitable container under the connection and wrap a thick layer of rags around the connection to prevent a possible jet of pressurized fuel from escaping. Slowly release and disconnect the fuel line and collect any escaping fuel in a container. Plug the line/connection to minimize fuel leakage and prevent dirt from entering the fuel system.
Pressure rise
5. After any work on the fuel system, pressurize the system as described below.
6. Fully depress the accelerator pedal, and then turn on the ignition. Keep the pedal depressed for about 1 second and then release it. After that, the ECU must activate the fuel pump for 20-30 seconds to fill the fuel system. After stopping the fuel pump, the ignition can be turned off.