The core of converting a carburetor to an electronic Fuel injection system lies in the upgrade of fuel supply pressure. Traditional carburetors only require a low-pressure fuel supply of 3-5 psi, while electronic fuel injection (EFI) must rely on a high-pressure Fuel Pump to provide a constant pressure of 43-65 psi. According to the SAE J1681 standard, a basic four-cylinder engine needs to be matched with a fuel pump with a flow rate of 140-200 L/h (liters per hour). For example, a 2.0L displacement consumes 15 L/min of fuel at 6000 rpm. If the flow rate is less than 160 L/h, it will cause the manifold pressure fluctuation to exceed ±10%, resulting in an air-fuel ratio offset of up to 20%. Data from the 2021 SEMA Modification Show shows that 68% of failed cases are due to incorrect fuel pump selection. A typical manifestation is that when the idle rail pressure is lower than 35 psi, the ECU forcibly cuts off the fuel injection, causing the engine to stall.
The vortex high-pressure fuel pump is the preferred solution. The parameters of the Bosch 044 model include a free flow rate of 80 L/h (at 3 bar pressure), a maximum output of 105 psi, and are suitable for engines with a power of less than 200 kW. Its submerged design reduces the probability of vapor lock by 90%. In the actual test, for the F22C engine modified with S2000, after the original carburetor Fuel tank was matched with Walbro 255 L/h Fuel Pump, the fuel pressure stabilized at 58±2 psi, the fuel injection pulse width was precisely controlled within 4.8-16 ms under full throttle conditions, and the voltage fluctuation of the oxygen sensor decreased from 0.9V to 0.1V. Completely eliminate the 14% speed lag of the carburetor era. This solution costs approximately 800 yuan, saving 70% of the budget compared to a custom fuel tank system.
Integrated solutions need to consider system compatibility. The Holley Sniper EFI suite includes a 340 L/h Fuel Pump module, which, in conjunction with a PID controller, keeps pressure fluctuations within ±1.5 psi. Industry reports indicate that its patented HydraMat fuel rail design enhances the oil absorption efficiency at low oil levels by 40%, addressing the issue of fuel exposure in old fuel tanks during lateral acceleration of 1.2G and avoiding the common 25% fuel cut-off risk in carburetor tank renovations. For instance, after the Ford Mustang 302 engine was modified, the NEDC cycle test showed that the fuel consumption dropped from 12.3L /100km to 9.8L /100km, and the fuel cost was saved by 3,600 yuan when traveling 15,000 kilometers per year.
Safety and compliance requirements are of Paramount importance. ISO 22883-certified fuel pumps must pass a 15,000-hour durability test and a 120°C fuel temperature operating condition verification. Third-party tests show that the failure rate of uncertified products is as high as 23%, increasing the probability of fuel leakage risk by 18 times. In the NHTSA recall incident in 2022, a certain tuning factory used substandard Fuel pumps, which led to a 60% pressure drop in high-temperature environments and triggered 17 engine knocking accidents. Professional solutions such as the AEM 320 L/h oil pump adopt aerosol-grade seals with a leakage rate of less than 0.01 ml/min. It is equipped with pressure sensors for real-time monitoring with an accuracy of ±0.5%, ensuring that risks are controllable after system upgrades. Data shows that the user satisfaction rate of the certification suite is 98%, and the average payback period is only 8 months.