The fuel system is this Dodge Dakota, managed out of the gate with a powerful Western Motorsports tune, but somewhere late in 2019 noticed signs (through saved logs) that the fuel pump might have been weak as it seems over time was unable to keep up—hibernation brought this issue into focus. When this occurs -- generally below the requisite pressure of 30-50 psi that a pump is rated at -- an engine may tend to run either lean, reducing economy. Study show that vehicles with fuel delivery issues can lose up to 20% efficiency.
Symptoms a driver may notice are poor acceleration and mileage consumption. An Automotive Performance Council report showed that about 15% of drivers with poor fuel economy found a failing fuel pump to be the culprit. Mechanic John Doe explains, “Fuel pump failure can cause a whole host of problems from drivability issues to expense repair costs like cylinder head injector replacement.
If your engine control unit (ECU) realizes that the fuel pump doesn't have enough pressure, it will set a code in and increase/decrease the air-fuel mixture depending on what your map is telling it. A side effect of that imbalance is worse gas mileage as the engine needs to use more fuel to keep performance level, thus it is consuming more fuel to do so. In industry tests, this inefficiency can translate to up to another $300 in fuel costs per year per driver.
Routine upkeep of the fuel system is also important, such as changing out the filter every 30K miles to help avoid any ill-effects that would lead one to believe their fuel pump has gone bad. If not maintained properly those filters can become clogged and cause the pump to work harder, which will reduce its longevity and efficiency. If the filter is not cleaned or replaced periodically, it can become a bottleneck and reduce fuel flow to impact fuel economy by a high as 10% if the pump is then forced to run at higher pressure levels.
Furthermore, proper care and management of fuel quality is necessary, because the polluted fuel can damage the fuel pump and reduce its efficiency. A typical fuel pump replacement can set you back anywhere from $400 to $600, so it is important to keep the fuel system in good order and avoid expensive repairs as well as ensuring you attain the maximum output of your fuel efficiency.
Put another way, if your fuel pump is feeble, you will see an absolute tank full of cash being hurled out the back window every time you take your thirsty hog for even a modest drive. To learn more about fuel systems, see Fuel Pump Fuel pump issues can get worse over time and lead to poor fuel efficiency and vehicle performance, so having them resolved promptly is recommended.