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Home >> Hyundai >> 2017 >> Azera Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnosis (1 Of 3) >> DTC P0087: Fuel Rail/System Pressure - Too Low >> System Inspection
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System Inspection

■ Check fuel leakage 

  1. Check following item visually.
    • Connector connection state.
    • Damage/connection state for vacuum hoses connected to fuel line.
    • Bent/pressed/twisted fuel line or fuel leakage.
  2. Has a problem found in this procedure?

    YES 

    NO 

    • Go to "Check Low pressure fuel line" as follows.

■ Check low pressure fuel line 

NOTE:
  1. Be cautious that Fuel is explosive and an empty fuel tank can still contain explosive gases. When working on fuel system make sure to supply adequate ventilation to the work area. Do not smoke, and keep sparks and open flames away.
  2. The fuel system remains under pressure when the engine is not running. Release fuel system pressure before disconnecting any fuel line to reduce the chance of personal injury or fire damage to vehicle components.
  1. IG "OFF" and disconnect Fuel Pump Relay in Junction Box.
  2. Start-up and wait until it stops itself.
  3. IG "OFF" and connect Fuel Pump Relay.
  4. Install the fuel pressure gauge to the delivery pipe with the fuel pressure gauge adaptor.
  5. Activate the fuel pump, and with fuel pressure applied, check that there is no fuel leakage from the pressure gauge or connection part.
  6. Measure the fuel pressure at idle.

    Specification:  490 ~ 530 kPa (5.0 ~ 5.4 kg/cm2 , 71.0 ~ 76.7 psi)

  7. Is the measured fuel pressure within specifications?

    YES 

    NO 

Condition Possible Cause
Fuel Pressure is too low Fuel filter, fuel pressure regulator, in-tank fuel hose or the fuel pump
Fuel Pressure is too high Fuel pressure regulator, hose or pipe

■ Check high pressure pump 

  1. Connect GDS to DLC (Data Link Cable).
  2. Start the engine and monitor "Rail Pressure Sensor" parameter on GDS at accelerating.
  3. Are the parameters displayed correctly?

    Specification:  the fuel rail pressure will be increased while accelerating the vehicle.

    Fig 1: Monitoring Rail Pressure Sensor Parameter On GDS At Accelerating
    G12087438Courtesy of HYUNDAI MOTOR AMERICA
  4. Are the parameters displayed correctly?

    YES 

    • Go to "Check injector" as follows.

    NO 

■ Check fuel leakage in injector 

  1. IG "OFF" after checking the fuel pressure test.
  2. Stop engine and check for a change in the fuel pressure gauge reading for 5 minutes.

    Specification:  After engine stops, fuel gauge reading is maintained for 5 minutes.

  3. Is the fuel gauge reading maintained?

    YES 

    NO