With insufficient fuel pressure, the following malfunctions are possible:
- unstable engine operation;
- stop the engine at idle;
- increased or decreased idle speed of the crankshaft;
- poor vehicle handling (engine does not develop full power);
- jerks and dips in the engine when the car is moving.
To begin with, we recommend checking the reliability of the electrical contacts in the wiring harness blocks of the injection system units responsible for fuel supply (fuel pump, injectors).
You can only check the fuel pressure in the power system with a pressure gauge with a hose and an adapter for connecting to the fuel rail.
1. Turn on the ignition and listen - within a few seconds you should hear the sound of the electric fuel pump. If the sound of the operation of the electric fuel pump is not audible, check the electric power supply circuit of the pump.
Note: If you turned on the ignition three times without trying to start the engine and the next time the electric fuel pump did not start, this is not a sign of a malfunction. It will turn on simultaneously with the start of the engine start by the starter.
2, Reduce the pressure in the power system (see «Reducing the pressure in the engine power system»).
3. Press the fuel hose end retainers and disconnect the fuel hose from the fuel rail fitting.
Note: When removing the hose, some fuel may leak out. Wipe it off with a rag.
4. To check the fuel pressure, connect a pressure gauge with a measurement limit of at least 5 kgf / cm2 into the gap between the fuel hose and the fuel rail fitting
5. Connect the wiring harness connector that was disconnected when the fuel pressure dropped to the fuel module and start the engine. With the engine idling, the pressure in the pipeline should be about 320 kPa (3.2 kgf/cm2).
The following causes of low fuel pressure are possible:
- faulty fuel pressure regulator (installed in the fuel module);
- fuel pump defective.
6. Stop the engine and reduce the pressure in the power system.
7. Disconnect the pressure gauge from the fuel hose and fuel rail fitting.
8. Connect the fuel hose to the fuel rail fitting.