Honda Civic Service Manual: Fuel Pressure Regulator P1 Removal and Installation (R18A9)

1.

Raise the vehicle on a lift, and make sure it is securely supported.

This procedure should be done outside in a well-ventilated area or in a properly equipped CNG shop.

This procedure will allow you to safely work on any part of the fuel system downstream of the manual shut-off valve, such as fuel pressure regulator P1 or the fuel injectors.

1.

Close the manual shut-off valve (A).

2.

Start the engine, and let it idle.

3.

After a few minutes, the engine will stall.

4.

Turn the ignition switch to LOCK (0).

NOTE: Set the wiper arms to the auto-stop position before removal.

1.

Remove the cowl top wiper covers (A).

2.

Remove the wiper arms (B).

1.

Remove the side cowl cover (A).

2.

The left side is shown; repeat on the right side.

1.

Remove the center cowl cover (A).

2.

Disconnect the windshield washer tube (B).

3.

If necessary, remove the hood rear seal (C).

1.

Remove the under cowl panel (A).

1.

Remove the fuel line (A) from the clamp (B).

2.

Remove the fuel pressure regulator protector (C).

3.

Remove the fuel feed hose (D), then disconnect the hoses (E) and the fuel line (F).

NOTE: Always use two wrenches when removing the fuel line nuts.

4.

Disconnect the connectors (G).

5.

Remove the bolts and nuts (H).

1.

Remove the engine undercover (A).

1.

Remove exhaust pipe A.

1.

Release fuel pressure regulator P1 (A) from the stud (B).

2.

Remove fuel pressure regulator P1 (C) from the front subframe rear side.

1.

Remove the stay (A).

1.

Install the stay (A).

1.

Insert fuel pressure regulator P1 (A) from the front subframe rear side.

2.

Set fuel pressure regulator P1 (B) to the stud (C).

1.

Wrap vinyl tape around the threads, and coat the surface of the tape with silicone oil or grease.

NOTE: Wrap the vinyl tape (A) so that there is no stepped portion.

2.

Install a new O-ring (A) into the groove.

NOTE: Be careful not damage the sealing face of the O-ring.

3.

Using a small brush, apply silicone oil or grease to the outer surface of the O-ring.

4.

Remove the vinyl tape.

1.

Install exhaust pipe A. Use new gaskets (B) and new self-locking nuts (C).

1.

Install the engine undercover (A).

1.

Install the bolts and nuts (A).

2.

Connect the connectors (B).

3.

Disconnect the hoses (C) and the fuel line (D), then install the fuel feed hose (E)

NOTE: Always use two wrenches when installing the fuel line nuts.

4.

Install the fuel pressure regulator protector (F).

5.

Install the fuel line (G) to the clamp (H).

1.

Open the manual shut-off valve (A).

Check for a gas leak if there is an odor coming from the vehicle. Compressed natural gas (CNG) can only be smelled, not seen.

1.

Open the hood and the fuel fill door.

2.

Connect a vacuum pump/gauge, 0－30 inHg, to the hose (A) from fuel pressure regulator P1, and apply 67.7 kPa (20.0 inHg, 508 mmHg) of vacuum.

3.

If fuel pressure regulator P2 does not hold vacuum, replace it before continuing to the next step.

4.

Inspect the fuel lines and hoses under the hood for kinks, abrasion, and other signs of damage.

5.

With the manual shut-off valve open, turn the ignition switch to ON (II), but do not start the engine.

6.

After the fuel pressure regulator shut-off solenoid valve/fuel tank internal solenoid valve operates for about 2 seconds, the fuel pressure in the fuel lines rises.

7.

Turn the ignition switch to LOCK (0).

8.

Repeat this two or three times.

9.

Within 1 minute, check for any damaged lines with a leak detector (A) (Snap-on Combustible Gas Leak Detector or Snoop Liquid Leak Detector (B)).

10.

If no damage was noticed during the inspection, turn the ignition switch to ON (II) for 2 seconds, then turn the ignition switch to LOCK (0).

11.

Within 1 minute, check for a leak at the vent hose outlet inside the fuel pipe protector (A).

12.

If you detect a leak, remove the vent hose, and check the fuel lines and fittings at the in-tank solenoid valve and the join block with a leak detector.

13.

If you cannot find the leak, raise the vehicle on a lift, remove the under-floor cover.

14.

Inspect all the fuel lines under the vehicle, visually, and with a leak detector.

15.

If you still cannot find the leak, remove the rear seat, then check all fuel lines and fittings at the fuel tank and the fuel joint block.

1.

Install the under cowl panel (A).

1.

If necessary, install the hood rear seal (A).

2.

Connect the windshield washer tube (B).

3.

Install the center cowl cover (C).

1.

Install the side cowl cover (A).

2.

The left side is shown; repeat on the right side.

NOTE: Set the wiper arms to the auto-stop position before installation.

1.

Install the wiper arms (A).

2.

Install the cowl top wiper covers (B).

1.

Fill the coolant reservoir to the MAX mark (A) with Honda Long Life Antifreeze/Coolant Type 2.