Fuel Injector Balance Test - Fuel Pressure Test
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.
- DO NOT perform the Fuel Injector Balance Test - Fuel Pressure Test if the engine coolant temperature (ECT) is above 94°C (201°F). Irregular fuel pressure readings may result due to hot soak fuel boiling.
- Verify that adequate fuel is in the fuel tank before proceeding with this diagnostic.
- Before proceeding with this test review the User Manual CH 48027-5 for Safety Information and Instructions.
- Install a fuel pressure gauge. Refer to Fuel Pressure Gauge Installation and Removal .
- Turn ON the ignition, with the engine OFF.
- 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.
- Command the fuel pump relay ON with a scan tool.
- Observe the fuel pressure gauge with the fuel pump commanded ON. The fuel pressure should be 345-414 kPa (50-60 psi).
- If the fuel pressure is not 345-414 kPa (50-60 psi), refer to Fuel System Diagnosis (NT7, NU1) or Fuel System Diagnosis (NU6) .
- Monitor the fuel pressure gauge for one minute. The fuel pressure should not decrease more than 34 kPa (5 psi).
- If the fuel pressure decreases more than 34 kPa (5 psi), refer to Fuel System Diagnosis (NT7, NU1) or Fuel System Diagnosis (NU6) .
- Perform the Fuel Injector Balance Test with Special Tool or the Fuel Injector Balance Test with Tech 2.
IMPORTANT:
IMPORTANT: