Caution: Following the procedure below will only relieve excess pressure in the fuel system. There will be gasoline left in the lines. Take all necessary precautions before disconnecting any fuel hose.
The fuel system discussed in this Chapter consists of a fuel tank, a fuel pump with a fuel gauge located inside it, a fuel filter, injectors or nozzles, a pressure regulator and various hoses and tubes. Inside all of these units, during engine operation (and also with the ignition on) the fuel is under pressure.
After the ignition is turned off, the pressure in the system remains for quite a long time. Before disconnecting any of the above components, the pressure must be relieved.
To do this, briefly open the fuel tank cap and close it again. Place a thick cloth on the connection. Use protective glasses. In the direct injection system aWA engines in the manner described, pressure can only be relieved in the part of the system that has low pressure (up to 6 atm.). To relieve high pressure (up to 110 atm.) special devices are required. High pressure in the system is present in the area from the fuel injection pump to the injectors 1.9L diesel engine the temperature of the fuel lines and fuel in an engine with pump-injectors in extreme cases can be up to 100°C. Before opening the connections, let the fuel cool down, otherwise it may cause a burn.
The simplest way to relieve pressure is the following. Remove the fuel pump fuse and start the engine. If the engine does not start, crank it with the starter for a few seconds, and if it does start, let the engine idle until it stalls. To completely relieve pressure, crank the engine with the starter a couple more revolutions. Turn off the ignition and replace the pump fuse.
Please note that if the pressure is released (or fuel has been removed from the system), the engine will take longer than usual to start. You will have to turn the engine crankshaft with the starter for at least a few seconds, during which the pressure in the system will be restored and the fuel will fill all the lines.