Warning! The fuel system of a fuel-injected engine has a pressure of 30 MPa (3 kgf/cm²). Therefore, it is prohibited to loosen the fuel line connections while the engine is running or immediately after it has been stopped. To work on the fuel system on an engine that has just been stopped, it is necessary to first reduce the pressure in the system. 2–3 hours after the engine has been stopped, the pressure in the system drops to almost zero.
To reduce the pressure, use a check valve installed at the rear end of the fuel rail and closed with a plastic cap. The valve is similar in design to a tire valve.
1. Unscrew the cap…
2. …press the valve, drain the fuel into a container specially prepared for this purpose.
Warning: Be careful - fuel under high pressure will spray out as a spray.
3. Tighten the plastic cap.
4. After this, you can disconnect the fuel lines.