Test Description
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Pontiac Grand Prix, 2003 Pontiac Bonneville, 2003 Chevrolet Monte Carlo, 2003 Chevrolet Impala, and 2003 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic procedure.
- 3 - The Engine Coolant Temperature (ECT) must be below the operating temperature to avoid irregular fuel pressure readings due to hot soak fuel boiling.
- 4 - The fuel pressure should be within the specified range. Refer to Fuel System Diagnosis if the fuel pressure is not within the specified range.
- 5 - The fuel pressure should reach a steady value. Refer to Fuel System Diagnosis if the fuel pressure does not stabilize.
- 6 - If the pressure drop value for each fuel injector is within 1.5 psi (10 kPa) of the average pressure drop value, the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting the second pressure reading from the first pressure reading.