Warning! Remember that gasoline is a highly flammable liquid! Observe all applicable fire safety precautions when working on power system components. Do not smoke! Do not approach the place of work with an open flame or carrying an unprotected lampshade! Do not service the system in rooms equipped with natural gas-fired heaters equipped with a pilot flame (such as water heaters and clothes dryers). Do not forget that gasoline is classified as a carcinogen, i.e., substances that contribute to the development of cancer! Try to avoid getting fuel on open areas of the body, use rubber protective gloves, in case of accidental unexpected contact with fuel, thoroughly wash your hands with warm water and soap. Clean up spilled fuel immediately and do not store fuel-soaked rags near open flames. Remember that the fuel injection system of models equipped with fuel injection is constantly under pressure. Relieve any residual pressure in the system before attempting to disconnect fuel lines. Wear safety goggles when servicing power system components. Keep a class B fire extinguisher handy at all times!
1. Relieve the pressure in the supply system (see Section Depressurizing the supply system).
2. Disconnect the negative cable from the battery.
Attention! If the stereo system installed in the car is equipped with a security code, before disconnecting the battery, make sure that you have the correct combination to activate the audio system!
3. Disconnect the pressure line from the outlet side of the fuel pump assembly.
4. Connect the dedicated fuel pressure test kit (tools D998709 and MD998742 complete with adapters, and sealing collars/gaskets). The adapter nozzle of a special pressure gauge is installed between the distributing tube and the pressure line - make sure that the joints are sealed tightly.
5. Connect the negative cable to the battery.
6. Apply battery voltage to the fuel pump activation terminal located in the engine compartment. Check joints for signs of leaks.
7. Run the engine to idle.
8. Read the pressure gauge and compare it with the regulations (see Specifications to Chapter Settings and ongoing maintenance).
9. Locate and disconnect the vacuum hose going to the fuel pressure regulator. Seal the open end of the hose immediately and read the pressure gauge again - the pressure should increase by approximately 0.7 kgf/cm2.
10. Restore the original vacuum hose connection. After the pressure stabilizes, rev the engine several times and check that the pressure does not drop when returning to idle.
11. Squeezing the return hose with your fingers, make sure that there is pressure in it when the engine speed is increased.
12. If the fuel pressure is too low, check the patency of the fuel filter, the condition of the regulator and the fuel pump. Replace defective units.
13. If the pressure is too high, the regulator should be replaced after making sure that there are no obstructions in the return hose.
14. If the pressure does not change when the vacuum hose is disconnected, therefore, there is a violation of the patency of the latter, or the regulator valve is stuck and the latter needs to be replaced.
15. Shut off the engine and follow the change in the pressure gauge - the pressure should not drop. If there is a slow decrease in pressure, there is most likely a leak at the injection injectors (check, replace defective components). A rapid drop in pressure indicates that the fuel pump control valve is stuck open - replace the pump.
16. Relieve pressure in the supply system (see Section Depressurizing the supply system).
17. Disconnect the pressure hose and remove the pressure gauge from the distribution tube.
18. After replacing the sealing ring, connect the hose to the tube, screw in and tighten the fixing screws.
19. When installation is complete, apply battery voltage to the pump enable terminal and inspect the assembly for signs of leaks developing.