Checking the fuel pressure in the fuel rail of the engine is only possible with a pressure gauge with a set of adapters for connecting to the fuel pipeline

Checking the pressure in the Renault Logan engine supply system

Turn on the ignition and listen: within a few seconds you should hear the sound of the electric fuel pump.

If you can't hear it, check the power supply circuit of the electric fuel pump.

Keep in mind that the electric fuel pump does not turn on if there is pressure in the fuel supply system.

In other words, if you previously turned on the ignition and tried to start the engine, then a serviceable electric fuel pump should have already created pressure in the system and not turning it on in this case is not a malfunction.

Checking the pressure in the Renault Logan engine supply system

Disconnect the pressure line from the fuel pump (see "Replacing the fuel pump").

To check the fuel pressure, connect a pressure gauge (with a measurement limit of at least 5 kgf / cm) between the fuel pump and the pressure pipe.

When the engine is idling, the pressure in the fuel line should be about 3 kgf/cm.

The following reasons for pressure drop are possible:

- faulty fuel pressure regulator;

Checking the pressure in the Renault Logan engine supply system

- clogged fuel filter;

Checking the pressure in the Renault Logan engine supply system

- faulty fuel pump

Pressure reduction in the supply system

The fuel in the supply system is under high pressure, so it is forbidden to loosen the fuel line connections while the engine is running or immediately after it has stopped.

To carry out work on the repair of the power supply system on a just stopped engine, it is necessary to first reduce the pressure in the power supply system.

2-3 hours after the engine stops, the pressure in the power supply system will drop to almost zero.

Turn off the ignition, open the hood and place it on the stop.

Disconnect the wire from the negative terminal of the battery.

Checking the pressure in the Renault Logan engine power system

Checking the pressure in the Renault Logan engine supply system

Press the left lock of the mounting block cover

Press the right latch of the mounting block cover, remove the cover

Checking the pressure in the Renault Logan engine supply system

Remove the fuel pump relay from the mounting block (shown by the arrow).

Connect the wire to the negative terminal of the battery, start the engine and let it run until the injector rail runs out of fuel.

The engine will then stop.

Turn off the ignition. Now you can disconnect the fuel lines.