Acura High-Pressure Fuel Pump

Chirping From Pump

MODELS

2014-‘18 MDX
2015-‘19 TLX
2014-‘18 RLX
2014-‘16 RLX Hybrid

SYMPTOM

The high-pressure fuel pump area chirps after the engine is warm.

POSSIBLE CAUSES

The high-pressure fuel pump is making a chirp. This noise does not impact the pump engine function or reliability.

CORRECTIVE ACTION

Replace the high-pressure fuel pump.

PARTS INFORMATION

Fuel Joint Pipe Set, 16012-R9P-315
High-Pressure Fuel Pump, 16790 — RLV-305
Intake Manifold Gasket (top), 17112-5G0 — A01
Intake Manifold Gasket, 17105-R9P-A01
Intake Manifold (RR), 17065-R9P-A01
Intake Manifold Gasket, 17055-R9P-A01

DIAGNOSIS

With the hood open, listen for a chirping noise with the engine warmed up.

If the noise is coming from the high-pressure fuel pump, go to the repair procedure.
If the noise is coming from the timing belt area, refer to service bulletin 14-025 for Timing Belt Chirps.
If the noise is not coming from the high-pressure fuel pump or timing belt, continue with normal troubleshooting.

REPAIR PROCEDURE

Relieve the fuel pressure.
Set the No. 1 piston at top dead center (TDC).
Remove the intake manifold and intake manifold base. Removal of the throttle body from the intake manifold is not required. Seal the two water hoses and leave the throttle body attached.
Remove the high-pressure fuel pump cover.
Remove the quick-connect ﬁtting cover.
Disconnect the quick-connect ﬁtting.
Remove the fuel joint pipe.
Disconnect the high-pressure fuel pump connector.
Remove the bolts by loosening them alternately, and then remove the high-pressure fuel pump and the roller.
Rotate the crankshaft and check the high-pressure fuel pump cam for pits, scores and excessive wear. If necessary, replace the rear camshaft.
Set the No. 1 piston at top dead center (TDC).
Install the roller onto the high-pressure fuel pump cam.
Set the gauge on the roller and hold it, and then set the dial to zero.
Rotate the crankshaft 720° and measure the height of the three cam lobes. If the cam lobes are excessively worn, replace the rear camshaft.
Note: The high-pressure fuel pump cam has three cam lobes. Cam lobe height Standard (new): 0.236 in (6.0 mm)
Set the No. 1 piston at top dead center (TDC).
Check the position of the cam that drives the high-pressure fuel pump as shown.
Coat the roller, O-ring and cam around the bore of the lifter with clean engine oil.
Install the roller and the high-pressure fuel pump. Install the bolts loosely by hand in an alternate pattern. Connect the connector.
Note: Failure to install a new fuel joint pipe will cause fuel leaks.
Lubricate the top of the new fuel joint pipe and the threaded area of the fuel rails and the high-pressure fuel pump with polyethylene glycol included in the new fuel joint pipe kit. Note: Do not reuse the fuel joint pipe.
Tighten the fuel joint pipe nuts by hand until the end of the joint pipe is seated on the fuel rails and high-pressure fuel pump.
Set the fuel joint pipe bracket on the cylinder head and loosely install the bolts
Tighten the high-pressure fuel pump mounting bolts to the speciﬁed torque.
Tighten the fuel joint pipe bracket mounting bolts and the fuel joint pipe nuts to the speciﬁed torque in the numbered sequence shown.
• A crowfoot-type special tool increases the torque applied by the torque wrench. Refer to torque speciﬁcations for details on how to recalculate the torque wrench setting. Failure to tighten the fuel joint pipe nuts to the proper torque will cause a fuel leak.
Connect the quick-connect ﬁtting and install the quick-connect ﬁtting cover.
Set the power mode to ON, but do not start the engine. After the fuel pump runs for about two seconds, the fuel line will be pressurized. Repeat this two or three times, then check for fuel leakage.
Install the high-pressure fuel pump cover and torque to 12 Nm (9 lb.-ft.)
Install the intake manifold.

Ever since the fuel pump was moved to the fuel tank, fuel pressure replaced the float height as a measure of fuel system health and performance. Checking the height of the float might have required some disassembly or special tools to bend the arms of the float.

When the shift was made to port or throttle body fuel injection, all a technician needed to diagnose a fuel problem was a set of “noid lights,” a fuel pressure gauge and maybe a multi-meter. Measuring the fuel pressure typically required checking the pressure at idle and under load. Most of the these tools can’t be used on the high pressure side of a direct-injection system because of higher pressures and changes in the injector location and technology.