Use the Fuel Injector Tester (J 39201) in order to energize the
injector for a precise amount of time, thus allowing a measured amount of
fuel into the manifold. This causes a drop in the fuel rail pressure that
can be recorded and used to compare to each injector. All injectors should
have the same pressure drop ± 10 kPa (1.5 psi).
The numbers below refer to the step numbers in the diagnostic table.
Step
| Action
| Value(s)
| Yes
| No
|
1
| Was the On-Board Diagnostic (OBD) System Check performed?
| --
|
Go to Step 2
| Go to
Powertrain On Board Diagnostic (OBD) System Check
|
2
| Was the Fuel Injector Coil
Test Procedure performed?
| --
|
Go to Step 3
| Go to
Fuel Injector Solenoid Coil Test
|
3
| Is the engine coolant temperature above the specified value?
| 94° C (201° F)
|
Go to Step 4
|
Go to Step 5
|
4
| Allow the engine to cool below
the specified value.
Is the engine coolant temperature below the specified value?
| 94° C (201° F)
|
Go to Step 5
| --
|
5
|
Caution: Remove the fuel tank cap and relieve the fuel system pressure before
servicing the fuel system in order to reduce the risk of personal injury.
After you relieve the fuel system pressure, a small amount of fuel may be
released when servicing the fuel lines, the fuel injection pump, or the connections.
In order to reduce the risk of personal injury, cover the fuel system components
with a shop towel before disconnection. This will catch any fuel that may
leak out. Place the towel in an approved container when the disconnection
is complete.
- Install the fuel pressure gauge.
- Energize the fuel pump using either the fuel pump test connector
or the scan tool.
- Place the bleed hose of the fuel pressure gauge into an approved
gasoline container.
- Bleed the air out of the fuel pressure gauge.
- Observe the reading on the fuel pressure gauge.
Is the fuel pressure within the specified limits?
| 284-325 kPa (41-47 psi)
|
Go to Step 6
| Go to
Fuel System Pressure Test
|
6
| Turn OFF the fuel pump.
Does the fuel pressure remain constant?
| --
|
Go to Step 7
| Go to
Fuel System Pressure Test
|
7
|
- Connect the J 39021 fuel injector tester to a fuel injector.
- Set the amperage supply selector switch ON the fuel injector tester
to the Balance Test 0.5-2.5 amp position.
- Turn the fuel pump ON and then OFF in order to pressurize the
fuel system.
- Record the fuel pressure indicated by the fuel pressure gauge
after the fuel pressure stabilizes. This is the first pressure reading.
- Energize the fuel injector by depressing the Push to Start Test
button on the fuel injector tester.
- Record the fuel pressure indicated by the fuel pressure gauge
after the fuel pressure has stopped moving. This is the 2nd pressure reading.
- Repeat Steps 1 through 6 for each fuel injector.
- Subtract the 2nd pressure reading from the 1st pressure reading
for one fuel injector. The result is the pressure drop value.
- Obtain a pressure drop value for each fuel injector.
- Add all of the individual pressure drop values. This is the total
pressure drop.
- Divide the total pressure drop by the number of fuel injectors.
This is the average pressure drop.
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 Step 8
| Go to
the Driveability Symptoms Tables
|
8
|
Notice: Do not repeat any portion of this test before running the engine in
order to prevent the engine from flooding.
Re-test any fuel injector that does not meet the specification.
Refer to the procedure in Step 7.
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 Step 9
| Go to
the Driveability Symptoms Tables
|
9
| Replace the faulty fuel injectors. Refer to the
Fuel Injector Replacement
.
Is the replacement complete?
| --
|
Go to Step 10
| --
|
10
|
- Using the scan tool, clear the DTCs.
- Attempt to start the engine.
Does the engine start and continue to run?
| --
|
Go to Step 11
|
Go to Step 2
|
11
|
- Allow the engine to idle until it reaches the normal operating
temperature.
- Check if any DTCs are set.
Are any DTCs displayed?
| --
| Go
to the Applicable DTC Table
| System OK
|
