In the article, we will look at how to check the fuel pressure and relieve the fuel pressure in the engine power supply system
Checking fuel pressure
If there is insufficient fuel pressure in the fuel rail, then it is possible:
- - stop the engine at idle;
- - unstable engine operation;
- - increased or decreased idle speed of the crankshaft;
- - poor engine response (engine does not develop full power);
- - jerks and dips in the engine when the car is moving
Before checking, you need to check the reliability of the electrical contacts in the wiring blocks of the injection system units responsible for supplying fuel (fuel pump, injectors)
To check the fuel pressure, you need a pressure gauge (with a measurement limit of at least 5 kgf / cm2) with a hose for connecting to the fuel line
Turn on the ignition and listen: for a few seconds, the sound of the electric fuel pump should be heard.
If you can't hear it, you need to check the electric power supply circuit of the pump
Electric fuel pump does not turn on if there is pressure in the fuel supply system
Relieve fuel pressure as described below
Disconnect the fuel supply pipeline from the fuel rail by sliding the clamps of the coupling
Connect a pressure gauge between the fuel supply line and the fuel rail
With the engine idling, the fuel pressure in the fuel line must be at least 365 kPa (3.65 kgf/cm2)
The following reasons for pressure drop are possible:
- the fuel pressure regulator is faulty (it is installed in the fuel module);
- clogged fine filter (installed in the fuel module);
- coarse fuel filter clogged;
- the electric fuel pump is faulty.
Fuel pressure reduction in the fuel system
Release or reduce fuel pressure when disconnecting fuel system elements
Preparing the car
Turn off the ignition and open the hood by pulling the hood latch handle
We press the lever, remove the safety hook from the latch and place the hood on the stop
Disconnect the negative battery terminal
Turn off the fuel pump by removing the fuel pump fuse or relay in the mounting block in the engine compartment
At the rear cover of the fuse box in the engine compartment, there is a diagram of the location of the fuses and relays
Connect the negative wire to the battery and start the engine
Let the engine run until the fuel rail runs out of fuel, after which the engine will stall
Turn off the ignition. Now you can separate fuels Wires