Fuel Injector Balance Test Procedure
Step
| Action
| Value(s)
| Yes
| No
|
1
| Did you perform the Powertrain
On-Board Diagnostic (OBD) System Check?
| --
|
Go to Step
2
| Go to
Powertrain On Board Diagnostic (OBD) System Check
|
2
| Did you perform
the Fuel Injector Coil Test?
| --
|
Go to Step
3
| Go to
Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F)
|
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 the scan tool.
- Place the bleed hose of the fuel pressure gauge into an approved
gasoline container.
- Bleed the air out of fuel pressure gauge.
- Use a scan tool in order to pressurize the fuel system.
- Wait for the fuel pressure to build.
Important: Repeat pressurizing the fuel system with the scan tool as necessary
to achieve the highest possible fuel pressure.
- 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 Diagnosis
|
6
| Turn OFF the fuel pump.
Does the fuel pressure remain constant?
| --
|
Go to Step 7
| Go to
Fuel System Diagnosis
|
7
|
- Connect the J 39021
Fuel Injector Coil/Balance 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 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 1st 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 gauge needle 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
Symptoms
|
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 still 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
Symptoms
|
9
| Replace the malfunctioning fuel injector(s). Refer to
Fuel Injector Replacement
.
Is the action complete?
| --
| System OK
| --
|
