Check fuel lines

Fuel pressure: 294-314 kPa

If the pressure exceeds the required values:

- Check the cleanliness of the fuel return pipe;
- If the fuel return pipe is clean, replace the pressure regulator.

If the pressure is below the desired value:

- Close the fuel return pipe, and check whether the pressure rises;
- If the pressure increases, replace a pressure regulator;
- If the pressure does not rise, measure the maximum pressure created by the fuel pump.