Table 1: | Injector Balance Test Example |
Table 2: | Fuel Injection Balance Test Procedure |
Cylinder | 1 | 2 | 3 | 4 | 5 | 6 |
---|---|---|---|---|---|---|
1st Reading | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) |
2nd Reading | 131 kPa (19 psi) | 117 kPa (17 psi) | 124 kPa (18 psi) | 145 kPa (21 psi) | 131 kPa (19 psi) | 130 kPa (19 psi) |
Amount of Drop | 165 kPa (24 psi) | 179 kPa (26 psi) | 172 kPa (25 psi) | 151 kPa (22 psi) | 165 kPa (24 psi) | 166 kPa (24 psi) |
Average Range: 156-176 kPa (22.5-25.5 psi) | Injector OK | Faulty injector - too much fuel drop | Injector OK | Faulty injector - too little fuel drop | Injector OK | Injector OK |
Numbers below refer to the step numbers on the diagnostic table.
The engine coolant temperature must be below the operating temperature in order to avoid irregular fuel pressure readings due to hot soak fuel boiling.
Tests the ability to achieve a specified fuel pressure range .
Tests the ability to maintain a steady fuel pressure value.
If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) of the average pressure drop value, the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting the second pressure reading from the first pressure reading. Refer to the Injector Balance Test Example.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 | Did you perform the Fuel Injection Coil Test | -- | ||
Important: Do not perform this test if engine coolant temperature is above 94°C (201°F) With a scan tool, monitor the ECT parameter. Is the ECT parameter less than the specified value? | 94°C (201°F) | -- | ||
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. Important: The fuel pump will run for approximately 2 seconds. Repeat as necessary in order to achieve the highest possible fuel pressure. Does the fuel pressure measure within the specified value? | 284-325 kPa (41-47 psi) | |||
After the fuel pump stops, the fuel pressure may vary slightly, then should hold steady. Does the fuel pressure remain constant within the specified value? | 284-325 kPa (41-47 psi) | |||
Does any fuel injector have a pressure drop value that is either higher than the average pressure drop or lower than the average pressure drop by the specified value? | 10 kPa (1.5 psi) | Go to Symptoms | ||
7 | Replace the faulty fuel injectors. Refer to Fuel Injector Replacement . Did you complete the replacement? | -- | -- | |
8 | Does any driveabilty condition still exist? | -- | Go to the applicable DTC table | System OK |