MFI Units
 

is there a major difference between a mfi unit from a 69 2.0S car compared to a 2.4t. can these units interchange or do they have to be recalibrated to specific motors.

Yes there is a difference, but not major. Your 2.0 S MFI pump has a enrichment solenoid and the 2.4 T does not. There are other internal differences also between the 2.0 and 2.4 MFI pumps. Can they be interchanged? Yes they can, but will need recalibration if you plan to put the 2.4 T on your 2.0 S.

I would also like to point out that the "space cam" in these pumps have different RPM/Fuel mapping, and although the pumps are interchangeable and can be adjusted to run with good AF ratios, there will be a difference in performance because of the 2.0 S MFI space cam and your S engine specs. compared to the 2.4 T "space cam" mapping.

You will have to recalibrate and space cams will not interchange between early and late pumps.

Right Aaron. You will have to recalibrate. Never said to swap space cams. I know about the change made on the 2.4 on up pumps. I was explaining the difference between the 2 pumps only.

Hi Mark, I agree with all you said. I read farther into his question just in case he went that route. I've been watching your Pump Dyno thread...very immpressive!