1. Prepare the vehicle for operations (see "Preparing a car for maintenance and repair").
2. To check the fuel pressure, unscrew the protective cap of the fitting installed on the fuel rail.
3. Put the pressure gauge hose with a special tip on the fitting.
4. Start the engine and check the fuel pressure when the engine is idling. The pressure should be within 2.8-3.2 bar (280-320 kPa).
The information is published on the website: VAZBOOK
5. Disconnect the vacuum hose from the pressure regulator and visually assess the pressure change. If the regulator is in good working order, the pressure should increase by 0.2-0.7 bar (20-70 kPa). Otherwise, the fuel pressure regulator must be replaced (see below "Pressure regulator - removal and installation").