FD2Envy

iTrader: (2)

What's good everyone!?

I just acquired a '99 spec long block which I will be installing into my '94 fd. I've read up on the differences within the wiring harnesses between jdm and usdm. My question for the gurus that have had experience installing S8 motors is if I purchase a S8-spec'ed Power FC, aside from re-pinning the dash harness for injector power, is there any other changes that need to be made to perform the swap, or could I then just drop the set right in?

Any help would be much appreciated.

Thanks in advance.

Narfle

iTrader: (16)

I think you'd be better off just swapping the accessories over to your new block and running the US harness.
I've got friend that did what you're attempting, and it's a lot of trouble for zero benefit.

FD2Envy

iTrader: (2)

Gotcha, cool, thanks. Would i be able to keep the black box under the intake manifold with the usdm wiring, or will i have to transfer all that over, too? I really figured using the s8 power fc would be the way to avoid swapping over the accessories :/

DaleClark

iTrader: (55)

Strip the block down to a short block and put it all back together with proper bits. Many of the things will work fine.

Yes, you do want to use the US wiring harness, trying to use the later harness is SUCH a massive pain for zero benefit as stated. Also, I don't see any good reason to run the later black box - much nicer to go simplified sequential and pick and choose what solenoids you want. The black box is all or nothing and really doesn't help or simplify anything at all.

Bringing it down to a short block and building it back up is FAR simpler and easier than trying to use the later harness. Like magnitudes simpler. You can also do all this with the engine on an engine stand, sitting by it comfortably in the garage. This is ALWAYS a good idea to do with a used engine, I would NEVER install an engine as-is off the pallet. Strip it down, go through everything, clean up everything, test everything. This is the time to do all that so you have a solid trouble-free engine you won't have to worry about down the road.

Dale

FD2Envy

iTrader: (2)

Thank you for your input as well. Looks like I have some work to do tomorrow night I'll just bite the bullet and swap over the accessories. Hopefully everything else goes smoothly, ordered new belts, fuel filter, and spark plugs. Fingers are crossed I don't run in to any hiccups, seems like a flipping solid motor, showed 120lbs on both rotors when I did the compression check!

Evadrepus

iTrader: (3)

I just did it to my car. The oil line to the turbos is different as is the water hard line from the throttle body to the water pump housing. Also, the LIM does not have "ports" going through it. I used the JDM three pipe set up instead of r&r the LIM.
Dave

FD2Envy

iTrader: (2)

thank you for that info! Were you able to swap over those lines from the usdm block, or did you have to make some fitment adjustments? the jdm LIM was one of the main reason I wanted just to purchase the S8 power fc, to bypass the emission stuff since all I'm really worried about is keeping the airpump.

Julian

iTrader: (14)

The latest JDM LIM with no pass thru ports is the same as the earlier JDM in other respects. I have at least one of each LIM made for this car.

DaleClark

iTrader: (55)

No reason you can't use the later JDM lower intake manifold with the earlier ECU and wiring. It all bolts up, you may just have to get a little creative with vacuum lines, but it's all easy.

Dale

FD2Envy

iTrader: (2)

ok, cool, I'll be pulling the motor tomorrow... looking forward to it! Thanks again for the information!

petros_rx7

I bring back this thread because I would like to do the same swap,to use 99 spec harness with 16 bit ecu from late models.
I think this is not for nothing.
If you open a 16 bit oem ecu the differents in electronics components is major.I believe that is very fast and with completely new maps and maybe better manage of peripherals.
Also many people believe that if you use pfc is the same pfc with s6 + models so no reason to swap to 16 bit harness.
This is not true the pfc for s6 + models have new cpu inside,more faster, with new redesign pcb.
So I thing that converting from 8 bit to 16 bit version it is not for nothing.
I have try to find 99 spec wiring schematicbut with out luck.
I dont know why nobody want to share this schematics.

FD2Envy

iTrader: (2)

I completely agree, which is why I decided to go against the grain and kept all the 99spec components and wiring harness, just waiting for my seriesV power fc to get here Only item i didn't keep was the jdm ecu just because California 91oct and the amount of advanced timing the jdm ecu is tuned for would not go well together. I wanted to keep the blackbox and was planning on going power fc in the first place, so there was no need to swap all the usdm emission stuff over.

petros_rx7

To connect the new pfc with your emmision harness is easy just plug the harness to pfc and install the 99spec harness with black box to your engine.
The problem is how to connect the main harness to 99 spec ecu.
I can help only with pinout of 16 bit ecu but in japanese. So someone have to translate it.
When this translation done everything will be clear and we can do the job correct.
Also i think 99 spec ecu have electric load unit inside so you have to remove and the elu from us spec rx7 and connect the elu wires on ecu direct.
I am sure that with 99 spec ecu or late model pfc the engine will work much better. I didnt mean more power maybe the power will be the same i mean better quality operation.

petros_rx7

here is the pinout and how to do the conversion harness from a japanese site.
I hope some one help as to figure it out.