Mustang EFI Donor w/speed density

[rock7174]

Alright my very first post.......I am in the middle of building a 67 and have a question about EFI. I bought a 1988 Mustang w/5.0 for next to nothing (after parting out, I actually made money). I want to use the entire engine and efi (bronco currently has a 289). Problem is it is a speed density setup and I want to convert to mass air. I plan on purchasing a new 5.0 harness (where I have not decided yet) to avoid hacking up the current harness to covert from SD to Mass Air, wiring into bronco harness and wiring multiple harnesses into one. I want the chances of having problems to be as small as possible. Do I need to change anything besides swapping for a mass air computer (A91 or similar), Mass air sensor, and housing to use for my swap?

 

[ransil]

Nothing wrong with using speed density.


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[rock7174]

If I chose to stay with speed density, can anyone recommend a harness to use with it (I will admit, I am no wiring genius and EFI is foreign to me)? I am leaning towards mass air in order to add some power to my bronco and from what I have read mass air works better with performance upgrades on engines.

 

[BUCKNBRONK]

even with s/d motor u will be happy with the power and performance. if u dont know that much about it then stick to the basics u can always up grade it later after u learn how they work. I went with centec for the whole rig including the efi swap.
I have a s/d motor- love it. just remember more power up front u have the stronger the rest has to be built, trans, tc, axles.

 

[EFI Guy]

Nothing wrong with using speed density.

I agree.

Speed density is just fine as long as you keep it relatively stock. If you start throwing hotter parts like cam or heads at it then that would be when MAF becomes a little more beneficial.

 

[needabronco]

If your 289 is in better shape, I'd use it over a tired worn out 5.0. Then its an intake manifold swap and wiring.

 

[ren71]

RJM harness is easy but $$$, or just add a mas air wiring conversion harness for $50 to use with the speed density harness. Follow the instructions and it's pretty easy. Ford Motorsport even offered it as a bolt-on for backyard mechanics.

Or like others said, get the speed density up and running first. You don't have to redo the speed density wiring when you decide to add the conversion down the line.

http://www.latemodelrestoration.com/item/PMA-EMAWH/1986-88-Mustang-50L-Mass-Air-Conversion-Wiring-Harness

 

[rock7174]

Both motors are in decent shape. I'm doing a frame off so I will rebuild either one. Using as a daily driver so after thinking about it I don't want to throw a ton of high performance parts in it. I emailed Ric Kolibar after reading through some efi threads and I think I will use the stock SD harness and have him covert it for my 67.......Like BUCKNBRONK said I can always change to Air Mass later. Thanks for the input guys.