Certainly, the last thing you want to happen is that acceleration is not as quick as it used to be thanks to a bad fuel pump which delivers fuel at an irregular rate. Given more or less gas than needed decreases miles per gallon and power; providing too much can flood the engine and provide poor performance. When the fuel pump is beginning to fail, it may not be able to provide the necessary fuel pressure for the vehicle, which can affect how well it accelerates and transition between gears. Depending on the vehicle, most require a fuel pressure of 30 – 80 psi (pounds per square inch) When the fuel pump delivers less than this, the engine will run out of fuel and accelerate slowly or inconsistently.
Another obvious sign of a fuel pump that is no longer working is hesitation or jerking during acceleration. So that's happening because the engine is not receiving sufficient fuel to accommodate this increased demand, especially when starting from standstill or trying to overtake another car on the highway. According to a report by the National Institute for Automotive Service Excellence (ASE), fuel system problems are now responsible for more than 10% of acceleration issues in cars brought in for service, including bad fuel pumps.
Fuel supply is stable as a consequence this has a secondary effect on acceleration. A weak or failing pump can cause the vehicle to do okay upon startup, and then suddenly have no power as the engine outpaces a fuel pump that isn't keeping up with more demand. And in some situations, the car could even stall during acceleration and that can be very dangerous for example on a busy road.
There was a high-profile example in 2019 with, again and naturally, faulty fuel pumps to blame that affected Honda and Subaru vehicles—a Toyota recall was not far behind. Hundreds of thousands of cars were affected by these recalls, showcasing the importance of having a fuel pump that properly operates.
Internal components of a pump such as the motor or valves can break down over time, lessening efficiency. Especially in some vehicles, a bad Fuel Pump can slow the acceleration by up to 30%, effecting overall driving performance greatly. Proper maintenance like changing the fuel filters and checking to see that the pump is functioning well can keep these problems from compounding.