Yes, a weak Fuel Pump can cause poor acceleration because it will not be able to supply the proper fuel pressure and flow to the engine. If the fuel pump is not able to maintain the required pressure in a normal system-use pressure, usually ranging from 30 to 80 psi for gasoline engines, then perhaps the engine is not getting the needed fuel to produce the requested power during acceleration. The result is often pronounced delay or sluggishness when the driver attempts to accelerate. These situations often lead to drops in performance of 10% to 20%.
For example, the Fuel Pump that acts to push the fuel inside the engine may struggle when worn out or has an internal failure under heavy load or during rapid acceleration. According to some studies, a 10 psi drop in fuel pressure can create an air-fuel mixture so lean that it is far from ideal for combustion. This leans the mixture beyond proper combustion and forces the engine to fight harder. Conversely, acceleration would suffer.
A low-voltage Fuel Pump often manifests as a symptom where, upon acceleration, there is a kind of surging feeling. This happens because the pump sometimes feeds fuel to the injectors, hence the fluctuating power delivered from the engine. Quite often, drivers will find themselves in situations where the car acts as if it is going to hesitate or lurch forward suddenly while the Fuel Pump struggles to maintain its proper flow. Over 500,000 vehicles from the 2019 model year showed different forms of complaints from owners of vehicles for faulty Fuel Pumps, which caused severe acceleration issues. These led to various recalls by manufacturers such as Ford.
Besides that, a weak Fuel Pump can also result in stalling when accelerating or driving on the highway. If the Fuel Pump is no longer able to manage the necessary pressure of fuel, the engine may suddenly just turn off, which, of course, is very dangerous on the road, especially in heavy traffic or on the highway.
As Henry Ford once said, one of the pioneers in the automotive world, "Quality means doing it right when no one is looking." This very principle directly relates to the importance of having a good Fuel Pump for ideal performance of the vehicle. Occasional checks and timely replacement in case of a weak Fuel Pump will rule out acceleration problems and provide smooth driving.
For more information on how to diagnose problems with the Fuel Pump and how it affects vehicle performance, see Fuel Pump.