If the engine will not start, crank the engine and measure the amount of fuel returned from the injectors.
NOTE: Do not exceed starter cranking limitations of 30 seconds. Wait 2 minutes before cranking again.
NOTE: For an accurate measurement, collect three different flows and average the results.
If the fuel flow is greater than specified, it will be necessary to perform the injector isolation test described below.
If the engine will start, start the engine.
Connect INSITETiol electronic service tool and start INSITETII electronic service tool Fuel Leakage Test and
allow the injectors to get up to operating temperature for at least 1 minute. By allowing the injectors to get up to
operating temperature, more accurate fuel flow measurements can be made.
NOTE: INSITEru electronic service tool Fuel Leakage Test is not available for front gear train engines. The test
must be run at standard idle conditions.
With the fuel drain hose in a graduated cylinder, measure the injector drain flow for 1 minute.
A leak may not be detected at standard idle conditions.
NOTE: For an accurate measurement, collect three different flows and average the results.
If fuel flow is greater than specification, it will be necessary to perform the injector isolation test described below.
Before attempting to isolate the leak, make sure that all the high pressure fuel connectors are tightened to the
correct torque value. Refer to Procedure 006-052 in Section 6.
If a connector is not tightened to the proper torque, tighten the connector and perform the previous test again. If the
injector return flow is greater than the specified flow rate, it will be necessary to block off the fuel to one injector at
a time to determine the location of the leak.
With the engine not running, remove the fuel injector supply line connecting the fuel rail to cylinder number 1.
Refer to Procedure 006-051 in Section 6.
Install the injector leakage isolation tool, Part Number 4918298, on the fuel rail where the number 1 cylinder fuel
line connects.
Torque Value: 40 Nโขm [ 30 ft-lb]
Repeat the leakage flow test with cylinder one blocked off and record the flow rate. Install the fuel injector supply
line. Refer to Procedure 006-051 in Section 6.
Repeat the leakage test with each cylinder blocked off.
Record the flow rate for each test.
The flow rate will decrease below the maxim um specified flow when the cylinder with the leak is blocked .
The table represents the results from a leakage test with a leak present in cylinder number 5 injector or high
pressure connector.
If this test is performed and there is not a significant change in fuel return flow while cutting out one injector,
there may be a problem with more than one injector.
Compare the fuel flow difference across all injectors. If there is more than one injector that caused a noticeable
decrease in flow, those injectors could be the injectors with the problems.
Another cause of this problem could be that the customer is operating on fuels lighter than specified.
Fuels with low viscosity will result in higher injector leakage and greater drain flow rates.
