| Table 1: | Example |
| Table 2: | Engine Coolant Temperature Outside 10°C - 35°C (50°F - 95°F) Test Procedure |
Diagnostic Aids
Highest Voltage Reading | Acceptable Subtracted Value Above/Below 10°C-35°C (50°F-95°F) | ||
|---|---|---|---|
7.1 Volts | 0.6 Volts | ||
Injector Number | Voltage | Subtracted Value | Pass/Fail |
1 | 9.8 | F | |
2 | 6.6 | 0.5 | P |
3 | 6.9 | 0.2 | P |
4 | 5.8 | 1.3 | F |
5 | 7.0 | 0.1 | P |
6 | 7.1 | 0.0 | P |
Test Description
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.
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The engine coolant temperature affects the ability of the fuel injector tester to detect a faulty fuel injector. If the engine coolant temperature is NOT Outside 10°C-35°C (50°F-95°F), go to Fuel Injector Coil Test Procedure - Engine Coolant Temperature Between 10°C-35°C (50°F-95°F).
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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 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. From the voltages recorded, identify the highest voltage, excluding any voltages above 9.5 volts. Subtract each voltage that is not above 9.5 volts from the highest voltage. Record each subtracted value (refer to the Example). The subtracted value for any fuel injector must not exceed 0.6 volt. A fuel injector with a subtracted value that is greater than 0.7 volt is considered faulty and must be replaced. A fuel injector with a recorded voltage above 9.5 volts is also considered faulty and must be replaced.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
Does the temperature measure outside the specified value? | 10°C-35°C (50°F-95°F) | |||
|
Important: The fuel system must not be pressurized.
Does any fuel injector have an erratic reading or a reading above the specified value? | 9.5 Volts | |||
4 |
Does any subtracted value exceed the specified value? | 0.6 Volts | Go to Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool | |
5 | Replace the faulty fuel injectors. Refer to Fuel Injector Replacement . Did you complete the replacement | -- | -- | |
6 | Does any driveabilty condition still exist? | -- | Go to Applicable Diagnostic | System OK |
