The fuel pump assembly is a critical component of the fuel delivery system, and if it fails, it can cause a range of problems with the engine's performance. 

Here are some signs that your fuel pump assembly may need to be replaced:

Engine won't start: If the fuel pump is not working correctly, the engine may not start or may start and then stall shortly afterward.

Engine sputters: A failing fuel pump may cause the engine to sputter or hesitate while running, particularly at high speeds or under heavy loads.

Loss of power: A failing fuel pump may cause a loss of power or acceleration, particularly when the engine is under heavy load.

Surging: A failing fuel pump may cause the engine to surge or fluctuate in speed while driving.

High-pitched sound: A failing fuel pump may emit a high-pitched sound, particularly when the engine is running at low speeds.

Fuel odor: A failing fuel pump may cause a fuel odor to be present around the vehicle, particularly near the fuel tank or fuel lines.

If you suspect that your fuel pump assembly may be failing, it is important to have it inspected by a qualified mechanic as soon as possible. Ignoring problems with the fuel pump can lead to more serious engine problems over time, and may even result in a breakdown or accident. A mechanic can diagnose the issue and determine if the fuel pump assembly needs to be repaired or replaced.