NOTE: This test only applies to engines equipped with EGR. Engines not equipped with EGR do not have a lift pump.
NOTE: High fuel inlet restriction can result in lift pump damage. Before replacing the lift pump, measure the fuel inlet restriction. Refer to Procedure 006-020, in the Troubleshooting and Repair Manual, ISBe, ISB and QSB5.9 (Common Rail Fuel System) Series Engines, Bulletin 4021271.
If service tool, Part Number 316461, lift pump performance test orifice, is not available, the following instructions can be followed to assemble the tool.
Install an M10 male Compuchek™ fitting, Part Number 3824842, on the diagnostic port on the inlet side of the fuel filter. Connect the service tool containing a 1.09-mm [0.043-inch] orifice, Part Number 3164621, to the diagnostic port.
Allow the other end of the hose to drain into a 500-ml graduated beaker, Part Number 3823705.
NOTE: This test is performed with the engine not running.
Start the lift pump by using the INSITE™ electronic service tool, lift pump override test. Refer to INSITE™ electronic service tool. Alternatively, the lift pump can be temporarily activated by “bumping” the starter without starting the engine or by turning the keyswitch on.
Measure the amount of fuel flowed by the lift pump in a 60-second interval:
Fuel flow rate for lift pump (engine not running) –
greater than 600 ml in 60 seconds or filling a 12-ounce can in 36 seconds or less.
NOTE: Voltage will only be present when the lift pump is commanded ON. This can be accomplished by either using the INSITE™ electronic service tool lift pump override test or by “bumping” the starter.
If the lift pump is not functioning properly, check the voltage and resistance at the lift pump.
If the voltage does not meet the specifications, check the power supply.
Thoroughly clean the fittings and components before removal. Make sure that debris, water, steam, or cleaning solution does not reach inside the fuel system.
Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.
NOTE: Make sure the inlet and outlet are properly oriented. Check the lift pump for labeling of inlet and outlet ports. Verify that the correct pump
(12 VDC or 24 VDC) is installed.
Install the lift pump on the mounting bracket behind the ECM cooling plate.
Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.
The fuel pump high-pressure fuel lines and fuel rail contain very high-pressure fuel. Never loosen any fittings while the engine is running. Personal injury and property damage can result.
It is not necessary to vent air from the high-pressure fuel system before starting the engine. Cranking the engine will prime the fuel system.
For engines with EGR, allow the lift pump to run by turning the keyswitch ON and waiting 30 seconds before starting.
Hello, I'm Jack, a diesel engine fan and a blogger. I write about how to fix and improve diesel engines, from cars to trucks to generators. I also review the newest models and innovations in the diesel market. If you are interested in learning more about diesel engines, check out my blog and leave your feedback.
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