MPFI .. SFI .. differences?

[pepsi_coke]

Ive been kind of wondering about this topic .. and wasnt able to find much on the net .. I have a 92 3.4L DOHC (MPFI) .. I was wondering if I could switch to SFI? Can I use SFI on OBDI, or that has nothing to do with anything?

I was thinking, is it the ECM thats sayin when to allow gas thru injectors? And if thats so, would a chip from here be able to do SFI, instead of MPFI?

Would this be an advantage? Possible? Any info would be good.. And on a side note .. what years of the LQ1 came SFI ?

Thanks
Jay

[joey b]

RE: MPFI .. SFI .. differences?

SFI was put into the LQ1 in 94. Yes, it tells the computer when to fire the injectors. I don't think that you can do it with OBD1, but I am not completely sure. It will improve gas mileage but as far as performance is concerned, it won't help any since it will run at MPFI at WOT.

[GnatGoSplat]

You would have to use a 94-95 PCM and wiring. They are OBD1. 91-93 PCM's don't have the necessary outputs to drive injectors sequentially.
You'd also need a camshaft position sensor. I'm not sure if one could be put into the existing head or not.

The gain wouldn't be worth the work, IMO.