3928143 Fuel Transfer Pump for Cummins 4BT 6BT Engine

3928143 Fuel Transfer Pump for Cummins 4BT 6BT Engine

The 3928143 fuel transfer pump is used for Cummins B Series diesel engine fuel supply applications. It is a mechanical fuel lift pump designed to move diesel from the tank side toward the engine fuel system before injection pressure is created.

This page focuses on 3928143 as the main part number. It is commonly referenced for Cummins 4B, 4BT, 4BTA, 6B, 6BT and 6BTA engine applications. Final fitment should be verified by the removed pump, mounting face, fuel line direction and engine configuration.

3928143 Reference Number Table

Fuel Supply Function

The 3928143 mechanical fuel transfer pump supports low-pressure fuel delivery for Cummins B Series engines. When the pump becomes weak or the suction side has air leakage, the engine may show hard starting, unstable idle, poor response under load or repeated fuel starvation.

This product should not be described as a high-pressure fuel injection pump. It belongs to the fuel supply side and should be selected by the old pump layout, not by engine model alone.

Common Failure Symptoms

• Hard starting: the engine may take longer to start when fuel delivery is weak.

• Unstable idle: air in the fuel line, weak pump output or loose fittings may affect idle stability.

• Power loss under load: restricted fuel flow may reduce engine response during operation.

• Fuel leakage: inspect the pump body, gasket, fittings and mounting surface.

• Repeated no-fuel condition: check the tank pickup, suction hose, fuel filter head and transfer pump function.

Troubleshooting Before Replacement

• Confirm the old pump number and compare it with 3928143.

• Check fuel filters, suction hoses, fuel tank condition and air leakage before replacing the pump.

• Inspect inlet and outlet fittings for incorrect installation, looseness or damaged threads.

• Check whether the engine has been rebuilt or modified with a different fuel system.

• Compare the pump lever, mounting holes, gasket shape and fuel line direction with the removed pump.

Installation and Maintenance Notes

• Clean the pump mounting surface before installation.

• Remove old gasket material to reduce fuel leakage and air entry risk.

• Confirm inlet and outlet direction before tightening fuel lines.

• Inspect or replace the fuel filter during pump replacement.

• Prime the fuel system after installation and remove air from the line.

• After startup, check for leakage, stable idle and normal response under load.

FAQ

Q: What is 3928143?

3928143 is a mechanical fuel transfer pump, also called a fuel lift pump or fuel feed pump, for Cummins B Series diesel engine fuel supply applications.

Q: Which engines are commonly referenced for 3928143?

Common engine references include Cummins 4B, 4BT, 4BTA, 6B, 6BT and 6BTA. The removed pump and engine configuration should still be checked before ordering.

Q: Is 3928143 a fuel injection pump?

No. It is a low-pressure fuel transfer pump. It should not be described as a high-pressure fuel injection pump.

Q: What should be checked before buying this pump?

Check the old pump number, mounting holes, pump lever, gasket shape, inlet outlet direction, fuel line fittings and engine model. Photos of the removed pump are recommended.

Q: Can Topvelsun help verify 3928143 before shipment?

Yes. Buyers can send old pump photos, engine nameplate, machine model and visible part number marks. Topvelsun can help compare the information before order confirmation.