Chart C-2A Injector Coil Test Procedure

Chart C-2A: Part 1 Of 3:

Injector Coil Test Equipment:

Test Result Calculation:

CHART TEST DESCRIPTION (Part 1 of 3)
Numbers below refer to circled numbers on the diagnostic chart.

1. This is the set-up step for performing the injector coil test. Also read instructions included with tools used for test.

2. Engine coolant temperature affects the tool's ability to detect a faulty injector. If engine coolant temperature is NOT between 50° F and 95° F the comparison chart (Part 2 of 3) must be used.

3. The first second of the voltage reading may be inaccurate due to initial current surge, therefore, record the lowest voltage displayed after the first second of test. The voltage reading should be within range (see example in accompanying image). The voltage reading may increase throughout the test as the injector windings warm and the resistance changes. An erratic voltage reading (one that jumps up and down) indicates an intermittent connection within the fuel injector.

4. To check the mechanical (fuel delivery) portion of the fuel injector, perform an injector balance test.

Chart C-2A: Part 2 Of 3:

Example #2:

CHART TEST DESCRIPTION (Part 2 of 3)
Numbers below refer to circled numbers on the diagnostic chart.

1. The first second of the voltage reading may be inaccurate due to initial current surge. Therefore, record the lowest voltage displayed after the first second of test. The voltage reading may increase throughout the test as the injector windings warm and the resistance changes. An erratic voltage reading (one that jumps up and down) indicates an intermittent connection within the fuel injector.

2. From recorded voltages (see example # 2 in accompanying image), identify the highest voltage reading recorded (other than those above 9.5 volts). Subtract all other voltages from the highest voltage recorded The subtracted value for any injector must not exceed 0.6 volt

3. To check the mechanical (fuel delivery) portion of the fuel injector, perform an injector balance test.

Chart C-2A (3 Of 3):

Chart C-2A: Injector Pressure Drop Procedure:

CIRCUIT TEST DESCRIPTION (Part 3 of 3)
Numbers below refer to circled numbers on the diagnostic chart.

1. Engine cool down period (10 minutes) is necessary to avoid irregular fuel pressure readings due to "Hot Soak" fuel boiling.

2. Fuel pressure should be within specified range. If not, refer to Chart A-7 Fuel System Diagnosis. Related Tests, Information and Procedures

3. Fuel pressure should hold steady. If not, refer to Chart A-7 Fuel System Diagnosis. Related Tests, Information and Procedures

4. If the pressure drop of all injectors is within 10 kPa (1.5 psi) of the average fuel pressure drop, the injectors are flowing properly. The actual amount of pressure drop is calculated by subtracting the second pressure reading from the first pressure reading.