clarification

clarification

1.8l 4cyl Dohc 16v Vvtl-i Sfi Engine

i was looking at the xrs on toyotas website. and thats all the info they gave up top. but i was wondering if anyone can tell me what Sfi meant.

it stands for sequential fuel injection... as opposed to throttle body injection or multi-port injection.

Sequential fuel injection is where the fuel injectors open individually at different times depending on which cyclinder they are pointed at. Multi port injection opens all of the injectors at the same time. The throttle body injection has the injectors at the throttle body.

damn dude you know your shit!...lol...

Standard Fuel Injection

just to add to what js10 said, sequential fuel injection opens the injectors in sequnce with you firing order, rather than all at once save gas and reduces detonation,as well as NOx emmissions.

you know i just learned something i was looking at that and was going to ask the same question

heh all this time i thought it stood for something else, meh learn something new

yeah, something that you may not know either is that (depending on the system) the injectors will usually squirt fuel onto the back of the closed intake valve. I think the SFI will squirt half of the fuel onto a closed valve, and the rest when the valve is open (straight into the cylinder). This two stage injection helps with the atomization of the fuel which helps with creating a homogeneous mixture, allowing for better combustion and a better charge. The fuel hits the back of the very hot intake valve and atomizes... which makes mix with the incoming air better.