Table 1: | Example |
Table 2: | Injector Flow/Voltage Drop Check |
The Injector Flow/Voltage Drop Check compares the fuel pressure drop when each injector is pulsed for a set amount of time. Since each injector pulses the same, the fuel pressure drop for each injector should be approximately the same. Any of the suspect fuel injectors can be identified by either a too high or a too low fuel pressure drop. This check also determines if the voltage drop of the injector is within specification. Injector voltage drop out of specification can cause driveability conditions that are intermittent or that do not show up during an injector flow check. This chart requires the J 34730-91 Fuel Pressure Gauge, the J 39200 Voltmeter and the J 39021 Fuel Injector Tester.
The number(s) below refer to the step number(s) on the Diagnostic Table.
Resistance Ohms | Voltage Specification at 10°C-35°C (50°F-95°F) | |
---|---|---|
16-17 | 7.75-8.75 | |
Fuel Injector Number | Voltage Reading | Pass/Fail |
1 | 8.3 | P |
2 | 8.1 | P |
3 | 8.0 | P |
4 | 8.1 | P |
5 | 6.5 | F |
6 | 8.5 | P |
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Did you perform the Powertrain OBD System Check? | -- | ||
2 |
Is the engine coolant temperature within the specified limits? | 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: 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 the specified limits? | 7.75-8.75V | |||
4 | Replace the malfunctioning fuel injector(s). Refer to the Fuel Injector and Fuel Rail Replacement . Is the replacement complete? | -- | -- |