Table 1: | Injector Balance Test Example |
Table 2: | Fuel Injection Balance Test Procedure |
Cylinder | 1 | 2 | 3 | 4 | 5 | 6 |
---|---|---|---|---|---|---|
1st Reading | 380 kPa (55 psi) | 380 kPa (55 psi) | 380 kPa (55 psi) | 380 kPa (55 psi) | 380 kPa (55 psi) | 380 kPa (55 psi) |
2nd Reading | 186 kPa (27 psi) | 170 kPa (25.5 psi) | 186 kPa (27 psi) | 235 kPa (34 psi) | 180 kPa (24 psi) | 201 kPa (29 psi) |
Amount of Drop | 194 kPa (28 psi) | 210 kPa (29.5 psi) | 194 kPa (28 psi) | 145 kPa (21 psi) | 200 kPa (29 psi) | 179 kPa (26 psi) |
Average Range: 179-200 kPa (26-29 psi) | Injector OK | Faulty injector - too much fuel drop | Injector OK | Faulty injector - too little fuel drop | Injector OK | Injector OK |
The numbers below refer to the step numbers on the diagnostic table.
The engine coolant temperature must be less than 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 more than 94°C (201°F). With a scan tool, monitor the ECT parameter. Is the engine coolant temperature 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 Step 7 as necessary in order to achieve the highest possible fuel pressure. Is the fuel pressure within the specified range? | 358-405 kPa (52-59 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 range? | 358-405 kPa (52-59 psi) | |||||||||
Does any fuel injector have a pressure drop value that varies from the average pressure drop by the specified value? | 10 kPa (1.5 psi) | Go to Symptoms | ||||||||
7 | Perform the Fuel Injector Cleaning Did you complete the procedure? | -- | -- | |||||||
8 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Symptoms |