The pressure in the fuel system of an engine with fuel injection is 30 MPa (3 kgf/cm 2 ).

Therefore, it is prohibited to loosen the connections of the fuel lines while the engine is running or immediately after it has been stopped.

To carry out repair work on the fuel system on an engine that has just been stopped, it is necessary to first reduce the pressure in the fuel system.

After 2–3 hours after the engine has been stopped, the pressure in the system drops to almost zero.

You will need a 10 mm wrench (preferably a socket wrench).

There are three ways to reduce the pressure in the fuel system.

Reducing fuel pressure Niva Chevrolet

In the first method, unscrew the engine control unit cover nut from inside the car and remove the cover.

Reducing fuel pressure Niva Chevrolet

Lowering fuel pressure Niva Chevrolet

Remove the electric fuel pump fuse.

Start the engine and let it run until the fuel line runs out completely.

The engine will then stall.

Reinsert the fuse.

You can also use a control valve mounted on the rear end of the fuel rail and covered with a plastic cap to reduce pressure.

The valve has a design similar to the valve core of a tire tire.

Reducing fuel pressure Niva Chevrolet

Reducing fuel pressure Niva Chevrolet

Unscrew the cap and, pressing the valve, drain the excess fuel.

After this, you can disconnect the fuel lines.

Be careful - fuel under high pressure will come out in the form of a spray torch

Another way to relieve fuel pressure:

Reducing fuel pressure Niva Chevrolet

Open the right cushion of the rear seat.

Reducing fuel pressure Niva Chevrolet

Bend back the sound insulation and unscrew it with a Phillips screwdriver. two screws for fastening the fuel pump hatch cover.

Lowering fuel pressure Niva Chevrolet

Remove the cover. Press the connector lock and disconnect the wiring harness connector from the fuel module.

After that, start the engine and let it run until it stops due to running out of fuel.

Turn on the starter again for 3 seconds.

After that, the pressure will be released.