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Topic: Brainstorming- 3.8 cfi to 5.0 cfi swap (Read 1129 times) previous topic - next topic

Brainstorming- 3.8 cfi to 5.0 cfi swap

Well, I think the ol' C5 in my vert is dying. Rather than doing anything to save it, I am thinking of ditching the 3.8/c5 setup. My old 83 is in a nearby junkyard, and I know the 5.0/aod in there are still in good shape.

If I grab the 5.0/aod, crossmember, motor mounts, and driveshaft, that should get it in there mechanically, right?

How about the CFI setup, does the 83 5.0 CFI differ from the 86 3.8 CFI? I wonder what is the minimum I can get away with swapping electrically... I'd rather not have to pull the whole 83's harness. If I have to pull the harness and all, there's a 4.6 DOHC Mark VIII sitting there too, I might as well just get that instead. I don't think I wanna get that involved in this swap though. Although a 4.6 DOHC vert would be the bee's balls.

Just thinking out loud. Anybody have any thoughts? I only consider this option because I personally know that 5.0/aod since it used to belong to me, and I can get it back for about the same price of a junkyard C5.
CoogarXR : 1985 Cougar XR-7

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #1
If the 83 CFI 5.0 was stock, it probable is EEC III. That is a big differance from an EEC IV.
Do you remember whether the 83 had a Duraspark ignition module or a TFI?

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #2
I believe it was EEC-III w/ duraspark
CoogarXR : 1985 Cougar XR-7

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #3
You won't need the crossmember/K-member as they are the same between the 2.3,3.8, and 5.0 cars. The only difference is the motor mounts. The only Fox K-member that has to be swapped to use a 302/5.0 in is a car that was originally equipped with a 200ci I6.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #4
I know the K-member is the same, but I thought the transmission crossmember was different? I read that on some mustang forum, the c5 mount was further up (supposedly you can cut/move/weld it to make it work, but I don't have a welder). Maybe that only applies to mustangs. I figured oh well, I know my old crossmember is the double-hump too (for dual exhaust). I haven't looked at this one yet to see if it is a single or a double.
CoogarXR : 1985 Cougar XR-7

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #5
I'm using the stock aod crossmember on my t-5, and it says the same thing.

For the work and effort involved, go 86 + fuel injection. No reason why not to.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #6
You could just put the AOD behind the 3.8.
I'm pretty sure you don't want to go to EEC III

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #7
The cfi wap would be plug and play through. Shouldn't need to change sensors/trans or any wiring unless there are differances in the wiring from year to year. Should be able to just drop it in re-using all existing parts.

I'd still do the 86 up sefi swap.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #8
Quote from: Haystack;410798
The cfi wap would be plug and play through. Shouldn't need to change sensors/trans or any wiring unless there are differances in the wiring from year to year. Should be able to just drop it in re-using all existing parts.

I'd still do the 86 up sefi swap.
The 83 EEC III CFI is a completely different animal. It has a different ignition system. There is no PIP emitter in the distributor. It has a CPS instead. There is no timing adjustment.
There is no self test connector to run test and pull codes. The ECU sensors have a 9V referance voltage instead of the 5 volts that EEC IV uses.

 

Brainstorming- 3.8 cfi to 5.0 cfi swap

Reply #9
welp, softtouch beat me to it.
EECIII is a unique animal unto itself.

an eecIV CFI V6 to an eecIV V8 would be a plug and play swap except the O2 may need to change out for fuel managment reasons.
For some reason i recall a pm discussion between me and masterblaster about this change over and he mentioned that the tables loaded to the EECIV CFI 6cyl was different in a couple ways compared to the cfi EECIV V8 but making sure you had blue top injectors and the correct 02 would allow you to use the v6 computer.

for general purposes, the 88 V6 cars are also only using two pins on the EEC to fire three injectors at once.... just throwing that out there.... the truck computers do the same,use only two pins to fire 4injectors at once so who knows.

I personally like CFI systems, my CFI v6 served me very well and with no head gasket issues but i wasnt and still am not a hot rodder.


I also owned a GM 2.5L 4cyl with a single injector,, now that car would not die (other than the plastic timing gear) that 83chevy citation earned its keep and got 35mpg