1991 Notchback 2.3L to SN95 5.0L Swap

[Foxboy91]

Hey I posted on this forum before about my SN95 not working and got it working from you guys.

My next question is a fairly complicated one, well to my knowledge, I have put the 5.0L into the foxbody already and I am about to tackle the wiring harness. What is the best way to approach this and what wires do I need from the SN95 to take to the Fox.

My approach to this was I am going to remove the wires from the Fox and just transfer the wires from the SN95 to the Fox.

If you guys have any advice on what I need to do or anything I'll appreciate it.

 

[tvsn95]

I have actual done this very swap,,What I learned is that you WILL need the underhood wiring harness for the 1991 V8 and change out the all the way to the ECU
Now understand . what I did was keep it all 1991. this allowed all the dash to work, IF you ARE swapping in the 1995 ECU you will need to build a pigtail or find and old ECU harness male plug and start cutting and soldering. ( 60pin to 104 pin}I have done this before also,,,I don't recomend this direction for the faint at heart.
The best and most likely cheapest and likely to succeed, Ideal will be to switch to a complete Holly system. Remember the SN95 computers were ONLY made 2 years, the 1991 is problematic /as is the SN95 stuff these days due to age. The baud rate is just awful also .
The common thing you are doing most guys just use a carburetor. of course you lose all you timing control and a bunch of other stuff . Ohh, and the plug for the fuel pump relay is under the drivers seat. It will accept the relay . and work.
Good luck

 

[Foxboy91]

Thank you! I am probably going to go the 91 route because i want the fuel system and dash/interior stuff to work without changing the ECU. But my question with the Holly system is it the EFI terminator X system that you just replace the whole wiring harness or is that completely wrong.

I want to know if i can use the same wiring harness for everything and just plug and play. or will i have to gut the whole wiring harnes.

 

[tvsn95]

If I did this again I would change the entire underhood wiring harness and use what Holley sells.( for engine control) the 30plus year old wiring and connectors are a problem.
the one thing I have always liked better about the older Fox is they don't use the CCRM like the SN95 and the 4cly cars. for what its worth. If I remember right the old 4cyl CCRM is the same as the SN95 ones. I could be wrong but it's worth looking at before you pitch it.
Just my 2 cents.
Ohh, and you will have some fun getting the connectors through the firewall ,,,as i remember.