Fuel Injector Balance Test-Fuel Pressure Test
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
DO NOT perform this 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.
IMPORTANT:
Verify that adequate fuel is in the fuel tank before proceeding with this diagnostic.
- Install a fuel pressure gage. Refer to FUEL PRESSURE GAGE 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 gage 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 .
- Monitor the fuel pressure gage 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 .
- Perform the Fuel Injector Balance Test with Special Tool or the Fuel Injector Balance Test with Tech 2.
IMPORTANT:
IMPORTANT:
The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant.