Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 3. The engine coolant temperature (ECT) must be below the operating temperature in order to avoid irregular fuel pressure readings due to hot soak fuel boiling.
2. 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.
3. 5. The fuel pressure should reach a steady value. Refer to Fuel System Diagnosis if the fuel pressure does not stabilize.
4. 6. If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) 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.

Fig 1: Fuel Injector Balance Test with Tech 2 (1 Of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Fuel Injector Balance Test with Tech 2 (1 Of 2)

Courtesy of GENERAL MOTORS CORP.