MFI fuel injection instead of carbs

[1971 911T]

does it make any sense to swap a 72-73 MFI unit (911T) into a zenith 911T (1971) ? get rid of the carb, which is almost impossible to tune just right that there aren't all those annoying misfire pops

what's the upside/downside?

thanks

[Walko]

upside throttle response
downside cost to install

My quick thoughts

Michael

[Bobboloo]

MFI isn't any easier to tune than carbs. Many would think quite the opposite actually. The upside is that once you do get MFI in tune it tends to stay that way for long periods of time.

Look at it this way. The Zeniths are tunable otherwise Porsche would have never used them in the first place. Switching to MFI would be trading one problem for another at this point and a more expensive problem at that. I think I would stick with the carbs and either find a Zenith carb guru or learn and become the Zenith carb guru.

[Zeke]

The question is, do you have the cam drive for the MFI pump? If not, this becomes more involved.

[Jim727]

What Milt said....

Having just converted my 2.2T to an MFI 2.2E, I think the best time to consider such a move is during an engine rebuild. Lots of different stuff - fuel pump, heads, cams, fuel filter console, enrichment system, heat plumbing to the thermostat, throttle bodies, etc.

MFI is great stuff, but not a casual change. I would seriously consider a thorough review of your Zeniths - meaning rebuild them then synchronize and tune meticulously. They're really good carbs. They're not difficult to rebuild if you're careful and have a good gasket kit, plus you'll learn a lot. The one bit that seems universally missing from the rebuild kits, however, is the overrun enrichment diaphragm. Be really careful with those.

Jim

[Danny_Ocean]

Not to hijack, but...sorta related:

I'm contemplating ditching the MFI for carbs (wanna buy a set-up, 1971 911T?). Are PMO's any better/easier to deal with than Zeniths (or others)?