In other words, a fuel pump doesn't manage the mixture but rather controls how much and at what pressure it sends gas to the engine which in turn changes your air/fuel ratio. The ECU and fuel injectors work in tandem to control the air-fuel ratio, adjusting it via real-time data from sensors like oxygen sensor and mass airflow sensor. For gasoline engines, the ideal air-fuel ratio is generally about 14.7:1 —this means that there are roughly fourteen and a half parts of open gas for everyone sectioned abrupt in with air. This balance allows full combustion with maximum efficiency.
It is equipped with an electric lift pump, in place of a mechanical one to ensure fuel delivery takes place at the proper pressure (usually 30-60 PSI as per vehicle requirements). If the fuel pump does not keep enough pressure in the system, your fuel injectors may suffer and end up with less than adequate supplies. When spark plug gaps are not properly set, this can lead to engine misfires and hesitation as well overheating. In the case of high-RPM, performance engines making in excess of 255 liters per hour (LPH) of flow need even more from their fuel pump. If that fuel ratio isn't correct, the air-fuel balance will be off and can drop efficiency by as much as 20 percent.
The fuel pump does not control the ratio, but its functionality can determine whether the system is able to maintain that desired mixture. The fueling system in the car has to be able match that increased demand for more fuel when operating at full boost -especially accomplishing this on a high performance vehicle. A weak pump can result in either a rich or lean condition, depending upon how it influences the fuel delivery process. A big automaker, meanwhile, initiated a recall in 2019 related to fuel pump malfunctions that could cause runs lean on some of its models and potentially damaging their engines if not addressed immediately.
Question: does a fuel pump mix up the fuel? The answer is, of course, no; however it has a very important part to play in ensuring the fuel system delivers just enough go-juice to maintain the desired air-fuel mixture. Detailed information on fuel pump can be found here.