The acceleration and overall power output of a car are all affected by such a poor fuel pump. The main function of the fuel pump is to keep a constant stream of gas flowing through the engine, thus maintaining stable gas pressure. If you have a Fuel Pump that is failing, or on its way out it throws off this delicate balance and doesn't deliver proper fuel delivery-head quarters where the AFM can't trigger the correct air-fuel balance leading to poor engine performance.
Under heavy load, this is another instance where you may experience a loss of power — if the fuel pump is failing and it cannot provide the engine with enough fuel (i.e. for acceleration). For engines that require a steady fuel pressure between 40-60 psi (pounds per square inch) to run properly, this drop in pressure due to a clogged or failing pump may cause sluggish performance and even stalling. In addition to harming performance, poor acceleration can pose safety risks—especially in maneuvers such as merging onto highways.
A bad pump will also spoil the fuel efficiency. This recipe compensates and usually is the major cause of an ineffective fuel combustion when the engine does not receive enough fuel. If a pump is not able to supply enough, it will lead to a 10–15% decrease in fuel efficiency which means, you will run out of money due to an increased cost at the petrol station. Also, spotty fuel supply usually exerts unusually high demand on the engine control module (ECM), forcing it to constantly fine-tune the performance of an engine so that misfiring, rough idling and in extreme cases even shutting down an engine can take place easily.
Poor running or flat spots at high RPM in performance applications — engines doing 7K or 8K need fuel flow, and a dodgy pump is going to kill the power. Fast conditions place a premium on stable, predictable fuel delivery–drop the ball for even just a moment and you can see as much as a 20% loss in power output (and therefore critical handling features and driver control). Keeping on track of car maintenance and replacing the parts when needed can help in preventing any failures or suboptimal performance.
High quality Fuel Pump Qualify the reliability of your engine by following Henry Ford's principle, "Quality means doing it right when no one is looking". A reliable fuel pump is essential to maintaining efficiency, power, and safe operation by delivering consistent flow and pressure of fuel.