| Table 1: | Example |
| Table 2: | Fuel Injector Coil Test - ECT within 10-35°C (50-95°F) |
| Table 3: | Example |
| Table 4: | Fuel Injector Coil Test - ECT Less Than 10°C (50°F) or Greater Than 35°C (95°F) |
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 between 10°C and 35°C (50°F and 95°F), go to Fuel Injector Coil Test Procedure - Engine Coolant Temperature Less Than 10°C (50°F) or Greater Than 35°C (95°F).
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The first second of the voltage displayed by the DVM may be inaccurate due to the initial current surge, therefore, record the lowest voltage displayed by the DVM after the first second of the test. The voltage displayed by the DVM should be within the specified range (refer to the Example ). The voltage displayed by the DVM 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.
Resistance Ohms | Voltage Specification at 10°C-35°C (50°F-95°F) | |
|---|---|---|
11.4-12.6 | 5.7-6.6 | |
Fuel Injector Number | Voltage Reading | Pass/Fail |
1 | 6.3 | P |
2 | 5.9 | P |
3 | 6.2 | P |
4 | 6.1 | P |
5 | 4.8 | F |
6 | 6.0 | P |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Is the engine coolant temperature within the specified limits? | 10°C-35°C (50°F-95°F) | Go to injector Coil Test Procedure -Engine Coolant Temperature Less Than 10°C (50°F) or Greater Than 35°C (95°F) | ||
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. Important: The Injector Selector Switch Box, and Fuel Injector Test Harness should be used inorder to prevent from removing the upper intake manifold to preform the injector balance test. Important: Check the engine coolant temperature again to ensure that the correct chart is being used. Important : The voltage reading may rise during the test. 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 limits? | 5.7-6.6 volts | |||
4 | Remove the upper intake manifold Refer to Upper Intake Manifold . Is action complete? | -- | -- | |
5 | Inspect fuel injector electrical harness for connector terminal damage, shorts, opens,and grounds. Was any of the above problems found? | -- | ||
6 | Repair Wires or Terminals As neccesary. Is Action Complete | -- | -- | |
7 | Replace the faulty fuel injectors. Refer to Fuel Injector Replacement Is Action Complete? | -- | -- |
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.
-
The engine coolant temperature affects the ability of the fuel injector tester to detect a faulty fuel injector. If the engine coolant temperature is between 10°C-35°C (50°F-95°F), go to Fuel Injector Coil Test Procedure - Engine Coolant Temperature 10°C- 35°C (50°F-95°F).
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The first second of the voltage displayed by the DVM may be inaccurate due to the initial current surge, therefore, record the lowest voltage displayed by the DVM after the first second of the test. The voltage displayed by the DVM 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.
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 |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Is the engine coolant temperature outside the specified limits? | 10°C-35°C (50°F-95°F) | Go to Fuel Injector Coil Test Procedure -Engine Coolant Temperature within 10°C-35°C (50°F-95°F) | ||
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. Important: The Injector Selector Switch Box, and Fuel Injector Test Harness should be used inorder to prevent from removing the upper intake manifold to preform the injector balance test. Important: Check the engine coolant temperature again to ensure that the correct chart is being used. Important : The voltage reading may rise during the test. Is any value that resulted from subtraction greater than the specified value? | 0.6 volts | |||
4 | Remove the upper intake manifold Refer to Upper Intake Manifold . Is action complete? | -- | -- | |
5 | Inspect fuel injector electrical harness for connector terminal damage, shorts, opens,and grounds. Was any of the above problems found? | -- | ||
6 | Repair Wires or Terminals As neccesary. Is Action Complete | -- | -- | |
7 | Replace the faulty fuel injectors. Refer to Fuel Injector Replacement Is Action Complete? | -- | -- |
