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.
1. Turn on the ignition and listen: within a few seconds you should hear the sound of the electric fuel pump. If it is not audible, check the electrical supply circuit of the electric fuel pump.
Attention! 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 its failure to turn on in this case is not a malfunction.
2. Disconnect the pressure pipe from the fuel pump (see «Fuel pump replacement»).
3. To check the fuel pressure, connect a pressure gauge (with a measurement limit of at least 5 kgf/cm2) between fuel pump and pressure pipe. With the engine idling, the pressure in the fuel line should be about 3 kgf / cm2.
The following reasons for pressure drop are possible:
- faulty fuel pressure regulator;
- clogged fuel filter;
- faulty fuel pump.
For solutions to these problems, see the subsection «Supply system».