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Home >> Chevrolet >> 2012 >> Cruze Eco, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 127 (Engine Controls And Fuel - 2.2L - Troubleshooting And Diagnosis) >> Fuel System Diagnosis (NU6) >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE:
    • The fuel pump relay may need to be commanded ON a few times in order to obtain the highest possible fuel pressure.
    • DO NOT start the engine.
  1. Ignition ON, engine OFF, command the fuel pump relay ON with a scan tool and observe the fuel pressure gauge while the fuel pump is operating. Verify the fuel pressure is between 345-414 kPa (50-60 psi).
    • If the fuel pressure is greater than the specified range, replace the fuel pump fuel reservoir pump fuel strainer orifice.
    • If the fuel pressure is less than the specified range, test, inspect, and repair the items listed below. If all items test normal, replace the fuel pump and the fuel pump fuel reservoir pump fuel strainer orifice.
      • Restricted fuel feed pipe
      • Restricted or plugged fuel filter
      • Restricted or plugged strainer
      • Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
  2. Verify that the fuel pressure does not decrease more than 34 kPa (5 psi) in 1 minute.
    • If the fuel pressure decreases more than the specified value, perform the following procedure:
      1. Ignition OFF, relieve the fuel pressure. Refer to Fuel Pressure Relief (With CH 48027) or Fuel Pressure Relief (Without CH 48027) .
      2. Disconnect the chassis fuel feed hose from the engine compartment fuel pipe. Refer to Metal Collar Quick Connect Fitting Service .
      3. Install the J 37287:  Adapter between the chassis fuel hose and the engine compartment fuel pipe.
      4. Open the valve on the J 37287:  Adapter.
      5. Ignition ON, command the fuel pump relay ON with a scan tool and bleed the air from the CH 48027:  Gauge.
      6. Command the fuel pump relay ON with a scan tool.
      7. Close the valve on the J 37287:  Adapter.
      8. Monitor the fuel pressure for 1 minute.
        • If the fuel pressure decreases more than 55 kPa (8 psi) within the specified time, replace the fuel pump and the fuel pump fuel reservoir pump fuel strainer orifice.
        • If the fuel pressure does not decrease more than 55 kPa (8 psi) within the specified time, locate and replace the leaking fuel injector(s).
  3. Relieve the fuel pressure to 69 kPa (10 psi). Verify that the fuel pressure does not decrease more than 14 kPa (2 psi) in 5 minutes.
    • If the fuel pressure decreases more than the specified value, replace the fuel pump.
  4. Operate the vehicle within the conditions of the customer's concern while monitoring the fuel pressure with the CH 48027:  Gauge. The fuel pressure should not drop off during acceleration, cruise, or hard cornering.
    • If the fuel pressure drops off, test, inspect, and repair the items listed below. If all items test normal, replace the fuel pump and the fuel pump fuel reservoir pump fuel strainer orifice.
      • Restricted fuel feed pipe
      • Restricted or plugged fuel filter
      • Restricted or plugged strainer
      • Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
  5. If the fuel system tests normal, refer to Symptoms - Engine Controls .
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