For 1990-2009 cars

Table 1: | Fuel Injector Coil Test

### Test Description

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

1. The first second of the voltage displayed by the DMM may be inaccurate due to the initial current surge, therefore, record the lowest voltage displayed by the DMM after the first second of the test. The voltage that is displayed by the DMM should be within the specified range, refer to the example. The voltage that is displayed by the DMM may increase throughout the test as the fuel injector windings warm and the resistance of the fuel injector windings changes. An erratic voltage reading, large fluctuations in the voltage that do not stabilize, indicates that there is an intermittent connection within the fuel injector.

Resistance Ohms | Voltage Specification at 10°C-35°C (50°F-95°F)
--- | ---
-- | 8.0-8.5
Fuel Injector Number | Voltage Reading | Pass/Fail
1 | 8.3 | P
2 | 8.1 | P
3 | 8.0 | P
4 | 8.1 | P
5 | 6.5 | F
6 | 8.5 | P

#### Fuel Injector Coil Test

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 |

1. Connect the scan tool.
2. Check the engine coolant temperature.

Is the engine coolant temperature within the specified limits?

10°C-35°C (50°F-95°F)

Go to Step 3

--

3 |

1. Turn OFF the ignition.

Notice: In order to prevent flooding of a single cylinder and possible engine damage, relieve the fuel pressure before performing the fuel injector coil test procedure.

2. Relieve the fuel pressure. Refer to Fuel Pressure Relief .
3. Access the main connector for the fuel injectors at the rear of the plenum.
4. Connect the J 39021-301 injector harness adapter to the main fuel injector connector.
5. Connect the injector harness adapter to the J 39021-210 injector switch box.
6. Connect the injector switch box to the J 39021 fuel injector tester.
7. Connect the fuel injector tester to B+ and ground on the vehicles battery.
8. Set the amperage supply selector switch on the fuel injector tester to the coil test 0.5 amp position.
9. Connect the leads from the DMM to the fuel injector tester. Refer to the illustration associated with the test description.
10. Set the DMM to the tenths scale (0.0).

Important: Check the engine coolant temperature again to ensure that the coolant temperature is within the specified limits in step 2.

11. Set the fuel injector switch box to the fuel injector to be tested.
12. Press the Push to Start Test button on the fuel injector tester.

Important: The voltage reading may rise during the test.

13. Observe the voltage reading on the DMM.
14. Record the lowest voltage that is observed after the first second of the test.
15. Repeat steps 11 through 15 for each fuel injector.

Did any fuel injector have an erratic voltage reading, large fluctuations in voltage that do not stabilize, or a voltage reading outside the specified limits?

8.0-9.0 V

Go to Step 4

Go to Fuel Injector Balance Test

4 | Replace the malfunctioning fuel injectors. Refer to Fuel Injector and Fuel Rail Replacement . Is the replacement complete? | -- | Go to Fuel Injector Balance Test | --