In general, it will need to keep the fuel pressure from 30-80 psi (pounds per square inch), but it can vary depending on what engine you have and if your car has a return or returnless system. Today, fuel injected engines are generally doing it at higher pressures (to make sure the pressure at which you deliver with as much force is up to 50 or even 60PSI) that have a good volume and air coming in ideal decomposition. Proper pressure is crucial for performance because low pressure can cause engine misfires, loss of power and bad fuel economy.
Alternatively, carbureted engines typically require less pressure (like 4-6 psi), because carburetor designs use vacuum to draw fuel in rather than requiring direct-pressure for injectors. A pressurized system can flood a carburetor leading to incomplete combustion or stalling of the engine if that pressure is too high. In both cases the fuel pressure must be precisely within manufacturer specifications for the systems to work properly and not cause damage.
Because fuel pumps are designed for a particular pressure, but problems such as partial failure of the pump itself or even a small particle stuck in your fuel filter can cause that precise pressure to be disrupted. By using fuel pressure gauges, technicians are able to measure these levels with precision so that they can uncover the cause of a suspected fuel system problem. Inconsistent pressure is often a sign of wear taking place within the fuel pump/related parts, and if you measure anything lower or even higher than recommended then it's likely time to have them attended.
Automotive News says that pressure-related problems account for 15 percent of fuel-induced failures, and low-pressure issues usually result from a declining pump or obstructed filter. Scheduled maintenance – such as a 30,000-mile fuel filter replacement – can ease pressure deviations by unloading the load on your pump and guaranteeing uniform flow.
For detailed advice on how to maintain and test fuel pressure, as well clues for troubleshooting common issues, Fuel Pump resources provide a helpful reference point so that car and truck owners keep their rides running at peak efficiency.