Fuel System - Overview
WARNING: This page is about a different car, the 2018 Ford F-550 Super Duty and 2018 Ford F-450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The gasoline fuel system consists of the following:
- 2-speed Mechanical Returnless Fuel System (MRFS) with MFI
- Fuel Pump (FP) module (located in the fuel tank)
- FP module that operates on 8 or 12.5 volts depending on load, that supplies fuel under pressure to the fuel rail
- Lifetime fuel filter (serviced as part of the FP module)
- Fuel tank filler pipe assembly
- Fuel tank
- Fuel and vapor tubes
The vehicle is equipped with electronic Multi-Port Fuel Injection (MFI) that is supplied by a 2-speed Mechanical Returnless Fuel System (MRFS). The PCM is able to maintain constant fuel pressure by varying the FP output. This is accomplished by increasing or decreasing voltage supplied by the fuel pump control module to the FP based on the duty cycle request from the PCM. The returnless fuel system offers improved economy, lower fuel temperatures and decreased fuel vapor in the fuel tank.