Fuel Line Pressure Inspection

WARNING:

Highly pressurized fuel may spray out if the fuel line is cut. Due to the following dangers occurring with a fuel spray, always complete the "FUEL LINE SAFETY PROCEDURE " to prevent the fuel from spraying.
- Fuel may cause irritation if it comes in contact with skin and eyes.
- If fuel ignites and causes a fire, it may lead to serious injury or death, and damage to property and facilities.
A person charged with static electricity could cause a fire or explosion, resulting in death or serious injury. Before performing work on the fuel system, discharge static electricity by touching the vehicle body.

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.

Complete the "BEFORE SERVICE PRECAUTION". (See BEFORE SERVICE PRECAUTION [SKYACTIV-G 2.5T] .)
Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Disconnect the quick release connector as shown in the figure below. (See QUICK RELEASE CONNECTOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)

Fig 1: Quick Release Connector
Courtesy of MAZDA MOTORS CORP.
Turn the lever of the SST parallel to the hose as shown in the figure below.

Fig 2: Turning Lever Of SST Parallel To Hose
Courtesy of MAZDA MOTORS CORP.
Insert the SST quick release connector into the fuel pipe until a click is heard.
Verify that the quick release connector is firmly connected by pulling it by hand.
Start the fuel pump using the following procedure.
Using M-MDS
1. Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
2. Connect the M-MDS to the DLC-2.
3. Using the simulation function "FP", start the fuel pump. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.5T)] .)
Without using M-MDS
1. Remove the fuel pump relay.
  
  Fig 3: Fuel Pump Relay
  Courtesy of MAZDA MOTORS CORP.
  CAUTION:
  - Short the specified terminals because shorting the wrong terminal of the relay and fuse block may cause malfunctions.
2. Using a jumper wire, short fuel pump relay terminals C and D in the relay and fuse block.
  
  Fig 4: Checking Fuel Pump Relay Terminals C And D
  Courtesy of MAZDA MOTORS CORP.
3. Connect the negative battery terminal and operate the fuel pump. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Operate the fuel pump for 10 s.
Measure the fuel line pressure.
- If not within the specification, inspect the following:
  If it less than the specification:
  - Fuel pump unit.
  - Fuel line for restriction or leakage
    If it exceeds the specification:
  - Fuel line restriction
    Fuel pressure
    
    545-695 kPa {5.56-7.08 kgf/cm2, 79.1-100.0 psi}
Stop the fuel pump using the following procedure.
Using M-MDS
1. Using the simulation function "FP", stop the fuel pump. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.5T)] .)
Without using M-MDS
1. Disconnect the negative battery terminal to stop the fuel pump. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Measure the fuel hold pressure after 5 min.
- If not within the specification, inspect the following:
  - Fuel line leakage
  Fuel hold pressure
  
  175-326 kPa {1.79-3.32 kgf/cm2, 25.4-47.2 psi}
Complete the "BEFORE SERVICE PRECAUTION". (See BEFORE SERVICE PRECAUTION [SKYACTIV-G 2.5T] .)
Disconnect the SST.
Connect the quick release connector. (See QUICK RELEASE CONNECTOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
Complete the "AFTER SERVICE PRECAUTION". (See AFTER SERVICE PRECAUTION [SKYACTIV-G 2.5T] .)