For 1990-2009 cars

Table 1: | Example

### Test Description

1. The engine coolant temperature affects the ability of the fuel injector tester to detect a faulty fuel injector.

2. 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 displayed by the DMM should be within the specified range. Review the example. The voltage 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 voltage that do not stabilize) indicates an intermittent connection within the fuel injector.

#### Example

Resistance Ohms | Voltage Specification at 10°C to 35°C (50°F to 95°F)
--- | ---
13.0-16.0 | 6.5-8.0 volts
Fuel Injector Number | Voltage Reading | Pass/Fail
1 | 7.7 | P
2 | 7.4 | P
3 | 5.8 | F
4 | 7.8 | P

Step | Action | Value(s) | 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 a scan tool.
2. Check the engine coolant temperature.

Is the engine coolant temperature within the specified limits?

10°C to 35°C (50°F to 95°F)

Go to Step 3

Go to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F)

3 | Caution: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete.

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.

1. Turn OFF the ignition.
2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .
3. Disconnect the fuel injector electrical connectors.
4. Connect the J 39021 fuel injector tester power leads to B+ and ground.
5. Set the amperage supply selector switch on the fuel injector tester to the Coil Test 0.5 amp position.
6. Connect the leads from the DMM to the fuel injector tester. Review the illustration associated with the test description.
7. Select DC voltage on the DMM and set to the tenths scale (0.0).
8. Connect the J 39021 fuel injector tester to a fuel injector.

Important:: Check the engine coolant temperature again to ensure that the correct chart is being used.

9. Press the Push to Start Test button on the fuel injector tester.

Important:: The voltage reading may rise during the test.

10. Observe the voltage reading on the DMM.
11. Record the lowest voltage observed after the first second of the test.
12. Repeat steps 8 through 11 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 of the specified value?

6.5-8.0 volts

Go to Step 4

Go to Fuel Injector Balance Test

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