Cummins ISX11.9 CM2250 – Service Manual 005-045   Fuel Lift Pump

The fuel lift pump is mounted to the electronic control module (ECM) cooling plate/fuel filter head behind the ECM.

NOTE: Not all ISX11.9 CM2250 engines are equipped with a fuel lift pump.

Use the following procedure for details on checking the fuel lift pump circuit. Refer to Procedure 019-397 in Section 19.

Use the following procedure for details on measuring the fuel lift pump output pressure. Refer to Procedure 005-236 in Section 5.

WARNING  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.

CAUTION  The fuel lift pump is extremely sensitive to debris. A small amount of debris in the lift pump can cause the lift pump to fail, causing it to need replacement. Only service the lift pump in clean areas and use care not to allow debris into the system.

• Disconnect the batteries. Refer to the OEM service manual.
• Remove the ECM. Refer to Procedure 019-031 in Section 19.
• Disconnect the engine wiring harness from the fuel lift pump.
• Remove the low-pressure fuel lines connecting the fuel lift pump to the fuel filter head. Discard the sealing washers. Refer to Procedure 006-024 in Section 6.

Remove the four capscrews from the fuel lift pump brackets.

Inspect the fuel lift pump brackets and rubber isolators. Replace if damaged.

Check the screen in the fuel lift pump inlet for debris. Backflow air through the lift pump if debris is found.

Inspect the fuel lift pump wires and electrical connector for corrosion or other damage.

CAUTION  The fuel lift pump is extremely sensitive to debris. A small amount of debris in the lift pump can cause the lift pump to malfunction, causing it to need replacement. Only service the lift pump in clean areas and use care not to allow debris into the system.

Install the fuel lift pump and brackets.

WARNING  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.

• Use new sealing washers and install the low-pressure fuel lines connecting the fuel lift pump to the fuel filter head. Refer to Procedure 006-024 in Section 6.
• Connect the wiring harness to the fuel lift pump.
• Install the ECM. Refer to Procedure 019-031 in Section 19.
• Connect the batteries. Refer to the OEM service manual.
• To verify the lift pump is not leaking, turn the keyswitch to the ON position with the engine off. Run the lift pump for 3 key cycles, and check for leaks.
• Operate the engine and check for leaks.