- check the condition and charge level of the battery and charge it if necessary;
- check the fuse in the fuel pump power supply circuit for proper operation;
- check the condition of the fuel lines and hoses for leaks;
Check the fuel pump's operation by ear. The assistant should turn the ignition key to the "ignition on" position, and you should hear a click and noise created by the pump within 2 seconds (the noise from the fuel pump is most easily heard through the fuel tank filler neck). If the fuel pump does not work, check the fuel pump electrical supply circuit. If the fuel pump is working but is not producing the required pressure, the pressure produced by the pump must be checked.
Checking the pressure generated by the fuel pump. To check the pressure in the fuel system, you must have a pressure gauge and an appropriate adapter for connecting to the fuel system, taking into account the following notes:
- on models produced before 2001, the fuel hoses are connected with hollow bolts and washers to the fuel filter, the fuel filter is mounted on a bracket on the left side in the engine compartment;
- on models produced since 2001, the fuel hoses are connected with quick-release connectors, the fuel filter is installed on the fuel pump block.
Relieve pressure in the fuel system.
Connect the pressure gauge to measure the pressure as follows:
Figure 5.1. Location of the hollow bolt securing the fuel outlet hose from the fuel filter on models produced before 2001
- on pre-2001 models, remove the relay and fuse box from the bracket and disconnect the fuel outlet hose from the fuel filter and connect a pressure gauge adapter to the fuel filter outlet (figure 5.1);
Figure 5.2. Fuel pipe connector location on 2001 and later models
- on models produced since 2001, disconnect the fuel line connector near the fuel distribution line and connect the pressure gauge adapter to it (figure 5.2).
Turn on the ignition, the fuel pump should run for 2 seconds.
Take readings from the pressure gauge. If the fuel pressure exceeds the nominal value, replace the pressure regulator. If the fuel pressure is below the specified value, the fuel filter and/or fuel lines may be clogged, there are fuel leaks, or the fuel pump and/or pressure regulator may be faulty.
Start the engine and warm it up to operating temperature. Check the fuel pressure. If the fuel pressure is below the nominal value and no obvious reason for this is found, the pressure regulator and/or fuel pump may be defective. In this case, it is recommended to replace the pressure regulator and fuel pump.
Turn off the engine and constantly monitor the pressure in the fuel system, which should be maintained constant. Five minutes after turning off the engine, the fuel system pressure should be 150 kPa. If the pressure drops significantly below this value, the pressure regulator and/or fuel pump are defective, or the fuel rail is leaking.
After checking the fuel pressure, relieve the pressure in the fuel system and disconnect the pressure gauge with the adapter.