Fuel Line Pressure Inspection

WARNING:

Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death. Fuel can also irritate skin and eyes. To prevent this, always complete the "BEFORE REPAIR PROCEDURE". (See BEFORE REPAIR PROCEDURE .)

CAUTION:

Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting using cloth or soft brush, and make sure that it is free of foreign material.

Disconnect the negative battery cable.
CAUTION:
- The quick release connector may be damaged if the tab is turned too far. Do not turn the tab over the stopper.
Disconnect the quick release connector from the fuel tank as follows:
1. Push the tab on the locking coupler 90 degrees until it stops.
2. Pull the fuel hose straight back.
NOTE:
- The stopper may be removed from the quick connector. Take care not to loose it. Reinstall it to the quick release connector before reconnecting the fuel line.
  
  Fig 1: Disconnecting Quick Release Connector From Fuel Tank
  Courtesy of MAZDA MOTORS CORP.
- The locking coupler has two internal locking tabs which retain the pulsation damper pipe. Be sure that the tab on the locking coupler is rotated until it stops to release two internal locking tabs.
Push the SST quick release connector into the fuel pipe and plastic fuel hose into the SST until a click is heard.

Fig 2: Locating Locking Tab
Courtesy of MAZDA MOTORS CORP.
Turn the lever parallel to the hose of the SST as shown.

Fig 3: Turning Lever Parallel To Hose Of SST
Courtesy of MAZDA MOTORS CORP.
Connect the negative battery cable.
Verify that the selector lever is in N range.
Start the engine and let it idle. Measure the fuel line pressure.
- If not a specified, inspect the following:
1. Zero or Low
  - FP circuit
  - FP
  - Fuel line (clogged)
  - Fuel leakage inside pressure regulator
2. High
  - Pressure regulator for high pressure cause
3. Fuel Line Pressure
4. 0.42-0.46 MPa {4.3-4.6 kgf.cm ² , 61-66 psi}
Observe the fuel pressure gauge indicator during heavy acceleration.
Verify that the fuel pressure fluctuation is within the specification during the test.
- If not a specified, inspect the following:
  - PCM
  - FP
  - Pulsation damper
  - Fuel line for improper routing, kinks or leakage
  1. Fuel Pressure Fluctuation
  2. 0.42-0.46 MPa {4.3-4.6 kgf.cm ² , 61-66 psi}
- Turn the ignition switch to the LOCK position.
- Measure the fuel hold pressure after 5 min.
  - If not as specified, inspect the following:
  - FP hold pressure
  - Fuel injector for leakage
  - Fuel line for improper routing, kinks or leakage
  1. Fuel hold pressure
  2. More than 0.176 MPa {1.79 kgf.cm ² , 25.5 psi}
- Disconnect the SST.
  NOTE:
  - A checker tab is integrated with quick release connector for new plastic fuel hoses. The checker tab will be released from the quick release connector after it is completely engaged with the fuel pipe.
  Fig 4: Disconnecting Checker Tab From New Plastic Fuel Hoses
  Courtesy of MAZDA MOTORS CORP.
- Inspect the plastic fuel hose and fuel pipe sealing surface for damage and deformation, and replace as necessary.
  - If the quick release connector O-ring is damaged or has slipped, replace the plastic fuel hose.
- Apply a small amount of clean engine oil to the sealing surface of the fuel pipe.
- Reconnect the fuel main hose to the fuel distributor until a click is heard.
- Lightly pull and push the quick release connector a few times by hand and verify that it can move 2.0-3.0 mm {0.08-0.11 in} and it is connected securely.
  - If quick release connector does not move at all, verify that O-ring is not damaged and slipped, and reconnect the quick release connector.
- Complete the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE .)