Fuel Injector Balance Test

Preliminary Checks

1. Verify spark or lack of spark available at each cylinder.
2. Verify fuel pressure and condition of fuel supply system.

Injector Balance Test Procedure

1. Connect a fuel pressure gauge to the fuel rail pressure connection.
2. Connect a Scan Tool, turn to "ON" and Select Special Functions, Fuel System - Injector Balance Test.
3. Select injector #1; the fuel system will prime. Record the initial pressure reading immediately after the fuel pump shuts off.
4. Press the soft key to pulse the first injector. Record the 'Pressure After Pulse' reading immediately after the injector stops pulsing.
5. Select and test each remaining injector. Be sure to record the Initial Pressure reading after each fuel system prime!

Injector Balance Test Analysis

1. Subtract the 'Pressure After Pulse' reading from the Initial Pressure reading for each cylinder, record as Subtracted Value.
2. Identify and record the 'Maximum Subtracted Value' and the 'Minimum Subtracted Value'.
3. Subtract the Minimum Reading from the Maximum Reading to obtain Max Difference.
4. If the Max Difference is less than 20 kPa (2.9psi), the injector are all flowing about the same and should not be replaced.
5. If the Max Difference is greater than 20 kPa (2.9psi), you have one or more faulty injector(s). Replace the injector that appears to be different than the rest (Injector #4 in the example above). Repeat the balance test with the new injector to make sure that Max Difference is now less than 20 kPa (2.9psi).