snakepitt1

Is it feasible and possible to convert a 2.4L MFI motor to the later CIS system? The motor in question is an early 1973 2.4L. Since there are seemingly only a handfull of people who know how to repair, modify or tune this system, I was wondering if anyone has ever simply swapped one for a later CIS system.

Scott
1973 2.4L MFI <img src="graemlins/c.gif" border="0" alt="[ouch]" />

Paul Brewer

CIS is a continuous mechanical fuel injection system. It's built like a swiss watch, which is to say it's as delicate as your MFI in some respects. It's more robust than MFI so I understand your desire to incorporate it. It's sensors are mechanical rather htan electrical and since it was never engineered for a 2.4 it won't be calibrated for that. If you made the switch you might have more driveability problems that you have with the MFI.

JSD

Anything is possible with the right sized check.
Why don't you join the Heart of Dixie PCA region
(one of the best for technical knowledge because of its proximity to Huntsville and all those engineers, scientists, and good ol boy racers)
and get some help on the MFI ?
I know there are a couple of semi-legendary reclusive Porsche techs in your neck of the woods.
Anyway, if you do decide on the change let me know if your MFI stuff will be for sale!

Chris Bennet

CIS uses different pistons and cams. It doesn't sound like a cost effective conversion.
Chris

James Achard

Scott, I would not do this conversion. The MFI system is built like a M1 Abrams tank and once it's working well you will love it. Please feel free to contact me on or offline with all that's been done as I have gone through MFI woes myself. My problems ended up costing nothing save some agressive cleaning to the warm up regulator.

Cheers, James

CamB

There are plenty of people who have spent the time to learn how MFI works and got it running well (I think they might be slightly masochistic, but they all exhibit the same glow of satisfaction afterwards).

Usually people ask the opposite question - how can I convert from CIS to MFI.

2 thoughts come to mind. The first is that you could swap to carbs.

The second is that you could swap the whole engine for something with CIS.

Both options are probably cheaper.

snakepitt1

James,
Problems with the MFI are as follows:
1. running extremely rich, to the point that my eyes were burning.
2. Popping out of the right(passengers side) side bank of stacks.
3. Will not idle at all with out keeping my foot on the gas.
4. When it did idle, the idle never went above 400 rpm at best, and the entire car would shake.
If you want to contact me my e-mail is
snakepittcomics@aol.com

Thanks,
Scott
1973 911T 2.4L MFI

Billy B

Snakepitt: When you get the MFI running right, it is the best! Hang in there. BB