Fuel Injector Balance Test Procedure
Step
| Action
| Value(s)
| Yes
| No
|
1
| Was the Powertrain 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: 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.
- Connect the J 34730
fuel pressure gauge to the fuel pressure test port.
- 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 Diagnosis
|
6
| Turn the fuel pump OFF.
Does the fuel pressure remain constant?
| --
|
Go to Step 7
| Go to
Fuel System Diagnosis
|
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 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 (refer
to (1) in the illustration).
- 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 (refer to (2) in the illustration).
- 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 faulty
fuel injector(s). Refer to the Fuel Injector procedure.
Is the replacement complete?
| --
| System
OK
| --
|
