SammyB1967

2009 STX Flairside SuperCab 4.6L with a "W" in the VIN. This is identified as a EFI 2V motor. I have confirmed this with Ford identifier and from the sticker price that came on the truck. This truck was built in 2009 in Kanas City since it was one of the last Flairside's made there. My issue is when I go and purchase parts at all the big boy auto parts store they ID my engine as a MFI. I have a better than general understanding of fuel systems but really don't know the difference. DOES ANY OF YOUR F150 EXPERTS KNOW THE DIFFERENCE BETWEEN EFI and MFI? Pictures

included of fuel rails.

Missmy06

There is no difference. EFI is electronic fuel injection and MFI is multi port fuel injection. MFI is a type of EFI. The only difference on the 09 4.6 is whether it is a 2 valve or a 3 valve engine.

SammyB1967

Thanks Missmy06 - I did figure it out doing some research. It seem the MFI system is different in only the way the way the fuel is sent though the fuel rails. Thanks for the reply and insight.