Genuine Acura Legend Fuel Pressure Regulator

Acura Legend Fuel Pressure Regulator Parts Questions & Experts Answers

• Regulator Assembly, Pressure
  16740-PH7-005
  Q: How does the fuel pressure regulator maintain constant fuel pressure to the injection system on Acura Legend?

  A: The fuel pressure regulator maintains constant fuel pressure to the injection system, and when the difference between the fuel pressure and the manifold pressure exceeds 36 psi, the diaphragm in the Fuel Pump is pushed up, allowing excess fuel to return to the Fuel Tank through the fuel return line. On Legend models, a pressure regulator cut-off valve controls the amount of vacuum to the pressure regulator. For vacuum checks on Legend models, inspect the fuel system for pinched or broken vacuum hoses and fuel lines, disconnect the vacuum line from the pressure regulator, and connect a vacuum gauge to the hose. Ensure the coolant temperature is below 221 degrees F before starting the engine and checking for vacuum; there should be vacuum present. If there is no vacuum, check the pressure regulator solenoid valve. After warming the engine above 221 degrees F, check again for vacuum; there should be none. If vacuum is present, check the pressure regulator solenoid valve again. If all pressure checks are correct, replace the fuel pressure regulator. For pressure checks, inspect the fuel system for issues, connect a fuel pressure gauge, and verify that fuel pressure rises after detaching the vacuum hose from the regulator. If it does not rise, pinch the fuel return line to see if pressure increases, indicating a need to replace the fuel pressure regulator. For solenoid valve checks on Legend models, ensure the coolant temperature exceeds 221 degrees F or the intake air temperature exceeds 176 degrees F, which will close off vacuum to the pressure regulator. Measure voltage at the 6P connector; if there is no voltage, repair the open circuit in the BLK/YEL wire. If there are no obvious open circuits, take the vehicle to a dealership for diagnosis. For further testing, start the engine, disconnect the appropriate vacuum hose, and check for vacuum. If there is no vacuum, inspect for blockage. Measure voltage at the 6P connector again; if there is voltage, check for a short in the light green wire. For replacement, detach the cable from the negative battery terminal, relieve the system fuel pressure, detach the vacuum and fuel return hoses from the regulator, remove the retaining bolts, and detach the regulator. Installation is the reverse of removal, ensuring to use a new O-ring and applying clean engine oil to it before installation to prevent damage.