Yes, the fuel pump can be a reason for car hesitation during acceleration when it is not pumping the right amount of fuel to the engine. When accelerating, if the fuel pump cannot maintain the pressure required-the ideal pressure ranges between 30 and 80 PSI-engine supply may be insufficient. This inconsistency causes a lean air-fuel mixture because of which the engine tends to hesitate, stutter, or lose power when more acceleration is demanded by the driver.
Fuel pumps wear out after a while, usually after 100,000 to 150,000 miles. As they do, their efficiency decreases considerably. The worn pump may just provide about 80% of the original fuel delivery; thus, it will need the engine to work harder than usual just to attain speed. And since the engine has to work harder than it needs to, its performance may consequently suffer from this, particularly in drawing fuel and making tachometer hesitation apparent.
Another factor is the fuel filter condition. A clogged filter restricts the fuel flow to the pump, which will be forced to work harder than it needs to and, probably, cause overheating in most situations. In every case when the fuel flow is impeded, drivers can feel hesitation, which concerns acceleration mostly. It is recommended that a fuel filter be replaced every 20,000 to 30,000 miles for optimum fuel flow and not to strain the pump.
It is also related to electrical problems when a fuel pump hesitates. Poor voltage supply due to malfunctioning fuel pump relay or wiring connections reduces the efficiency of the fuel pump. A drop in voltage below 12 volts can cause up to 15% reduction in fuel delivery efficiency, creating engine hesitation when extra power is called upon. Regular inspection for worn-out electrical connections and their replacement will ensure the pump gets stable power.
In general, the failure in the Fuel Pump-both in terms of not providing adequate pressure or flow of fuel-can lead to hesitation in the engine upon acceleration. Preventive measures include regular maintenance in replacing fuel filters, electrical system checks, among other necessary servicing.