Warning! Remember that gasoline is highly flammable! When working with fuel system components, observe all accepted fire safety measures. Do not smoke! Do not approach the work area with an open flame or unprotected portable appliance! Do not service the system in rooms equipped with natural gas heating devices equipped with a pilot flame (such as water heaters and clothes dryers). Do not forget that gasoline is a carcinogen, i.e., a substance that promotes the development of cancer! Try to avoid fuel coming into contact with exposed areas of the body, use rubber protective gloves, and in case of accidental contact with fuel, wash your hands thoroughly with warm water and soap. Collect spilled fuel immediately and do not store rags soaked in fuel near open flames. Remember that the fuel system of models equipped with fuel injection is constantly under pressure. Before disconnecting fuel lines, relieve residual pressure in the system. Wear safety glasses when servicing fuel system components. Always keep a Class B fire extinguisher on hand!
1. Release the pressure in the fuel system (see Section Relieving pressure in the fuel system).
2. Disconnect the negative cable from the battery.
Warning! If the car stereo system is equipped with a security code, make sure you have the correct combination to activate the audio system before disconnecting the battery!
3. Disconnect the pressure line from the outlet side of the fuel pump assembly.
4. Connect a special fuel pressure measuring kit (tools D998709 and MD998742 complete with adapters and sealing cuffs/gaskets). The adapter of the special pressure gauge is installed between the dispensing pipe and the pressure line - make sure that the joints are sealed securely.
5. Connect the negative cable to the battery.
6. Apply battery voltage to the fuel pump activation terminal located in the engine compartment. Check the joints for signs of developing leaks.
7. Start the engine at idle speed.
8. Read the pressure gauge reading and compare it with the standard requirements (see Specifications in Chapter Settings and ongoing maintenance).
9. Locate and disconnect the vacuum hose going to the fuel pressure regulator. Immediately plug the open end of the hose and read the pressure gauge again - the pressure should increase by approximately 0.7 kgf/cm².
10. Reconnect the vacuum hose to its original position. Once the pressure has stabilized, rev the engine several times and check that the pressure does not drop when returning to idle.
11. Squeeze the return hose with your fingers to ensure that there is pressure in it when the engine speed increases.
12. If the fuel pressure is too low, check the fuel filter for patency, the condition of the regulator and fuel pump. Replace defective components.
13. If the pressure is excessively high, replace the regulator, having first made sure that there are no obstructions in the return hose.
14. If the pressure does not change when the vacuum hose is disconnected, then the latter is blocked, or the regulator valve is stuck and needs to be replaced.
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15. Turn off the engine and watch the pressure gauge readings change - the pressure should not drop. If the pressure drops slowly, there is most likely a leak in the injection injectors (check, replace defective components). A rapid drop in pressure indicates that the fuel pump check valve is stuck open - replace the pump.
16. Release the pressure in the fuel system (see Section Relieving pressure in the fuel system).
17. Disconnect the pressure hose and remove the pressure gauge from the dispensing tube.
18. After replacing the sealing ring, connect the hose to the tube, screw in and tighten the mounting screws.
19. Once installation is complete, apply battery voltage to the pump activation terminal and inspect the assembly for signs of developing leaks.