Can the stock engine harness off of an S5 J-spec 13BT be used with the stock interior harness or an S5 NA convertible RX-7???



There are some plugs on the stock NA motors engine harness that came out of the car, that are not on the J-spec engine's harnes.

Also we don't see the plug that goes to the knock box on the interior harness of the car.....



Any information on this would be appriciated. And my appologies if this has been covered many times....

 

s5's TII's dont have "knock boxes". they are built into the ECU.

and obviously the NA (your vert) wouldnt even have a knock box anyways because stock its soo far from knocking (compared to a TII engine) that it makes me cry myself to sleep.

cliff notes:
NO NA's have knock boxes.
NO s5's have knock boxes (TII ECU's have them built in)
only S4 TII's have "knock boxes"

 

Alright.


Thanks for those answers, but can I use the stock J-spec wiring harness? Does anyone here know? Or is everyone spitting out second, third, fourth, fifth.... hand information?


It seems like all you would have to do is extend a couple of wires, and it would work. Or is there something missing?


I'll find out in a day or so, if no one has an answer.

 

All you have to do.....is copy down the input/output of the series five non turbo and compare it to the series five turbo input/outputs. In the manual there are a couple of pages that do just that. They list each pin for each plug for the non turbo and the turbo. If the series five is anything like the series four, there are only four to five wires that even need a second look. Probably fewer on a series five. Yes. It's just a matter of adjusting the length of a few...very few wires and making the neccessary adjustment to the connections.

The only problem with this approach is....... I've a sneaking feeling there are a whole lot more people who have not a clue about what goes where or why on their engines. Examples are of people *removing the rat's nest*. Commoly called the DUMB AS A ROCK MOD. oooPS Did I offend anybody???? HOpe so.

 

So it will work....



Thank you for the input!



And, now you just worried me. Why is removing the rats nest bad?

 

Comparing series five turo vs non turbo pin outs: There would at first glance appear to be SIX differences........but not really.

Pin 1T seems to be diff but is not. Leave as is.

Pin 1U seems different, but leave as is.

Pin 2M is the Knock Sensor on a Turbo and its for the VDI solenoid on a N/A. Cap the Black/white wire on the N/A cars solenoid and splice a piece of wire to the remaining wire and terminate that new wire at the Knock Sensor on the turbo engine. Done.

Pin 3I is for the Split Air Solenoid Valve on the ACV. JDM ACV have no Split Air Solenoid. Either cap that wire or install a USA ACV. The N/A ACV won't work on a turbo engine.

Pin 3N is for ECAT (auto trans) on a N/A and not used at all on a Turbo.If you did not have a auto trans.....do nothing once more.

Pin 3R is for the Turbo Duty Solenoid on...a turbo. It's used for the six ports on a non turbo. Two ways to deal with this. One is to make this existing solenoid the Turbo Duty solenoid, but you must make sure the vac routing to the turbo is run right/correct.....Or just don't use this wire for anything and buy a manual boost controller and attach it to the series five turbo. I'd opt for the manual boost controll so you can raise the boost to 10psi with a allen wrench (some what risky, manual boost controllers are/seem spikey to me, no real long time experiece for me on that, so take it for what it's worth).

So looking at the list above, what do I come up with??? Just two wires that need retrofit. Big deal. I trust your going to buy a aftermarket boost gauge so your not interested in having a boost gauge in the combination meter. Good move.

 

So I have some questions. Does the JDM engine you are putting in have the solenoid rack/hoses/piping???? Or is it bare block with just the wiring?

As a note: Look at the turbo. At the front of the turbo should be the waste gates diaphram with short hose going to a small pipe that curves around the front of the compressor and goes to a nipple on the discharge pipe on the turbo compressor. That line that curves b/t those points should also have a nipple coming off it. THAT nipple is meant to go the the Turbo Duty Solenoid. So if you did not want to do the wiring on that duty solenoid, you could just cap off that nipple. The turbo will only boost to approx 5psi that way, but you could at least be on the road til you have time to mess with the Duty Solenoids wiring.

 

The attached jpg shows the hard line on the turbo and the nipple that goes to the Turbo Duty Solenoid. If capped off.....the turbo will boost only to approx 5 psi.....but it will boost til you get the solenoid issue out of the way. http://www.teamfc3s.org/forum/showth...threadid=32481

Are we to assume your using a Turbo ECU and Turbo boost/pressure sensor?

 

jdm harness goes to the other side of the car, so its constuction is a little different. it should still work though.

 

yep that removal causes more problems than it ever "fixed", if you cant figure out 10 vacuum lines....

 

Big ooops on my part. I NEVER even considered that aspect.

 

The JDM harness is missing a large plug on the inside of the car. You'll be missing street-necessary functions such as wipers, cruise, temperature gauge in dash, air blower motor, and others. IF you check your old NA harness, it had 2 plugs on the ecu, and 2 plugs for the interior harness; the JDM harnesses have 2 plugs for the ecu and 1 plug for the interior.

IT is a stretch, but it will physically fit from the engine to the computer. IT will operate the engine, but you won't wanna run on the street this way. My vert was this way when I bought it, one of the reasons I got it for almost nothing.

 

The engine was a full long block with EVERYTHING exept the BOV. It even came with an FCD.



Everything is turbo in the car.... All the way back to the differential/half shafts.




It's plugged into the ECU right now, so it fits rather easily once you take the intake off, and move it around a little bit.






That was exactly what I was wanting in an answer!!!! I noticed that huge plug that was missing from this harness.... Figured it might have been something from the automatic.....


Well, this harness will still let me start the engine up until I get a USDM one.



Wow... Thank you for all the information!

 

Welllllll.........I'd chunk the JDM harness in a heartbeat and leave the original USA non-turbo harness in the car. Plus it will connect right up to a turbo ECU. Everything should work as it did prior to putting in the turbo engine. No plugs left off etc.

For the life of me I'll NEVER EVER understand why anyone would go to the bother of buying a turbo harness. It's a concept that's waaaay over my head.

 

THE NA ONE WORKS ON TURBO'S??????


You aren't jerking my third leg are you? being a **** sales men, with a mouth full of samples?


Banzi.... I'm stealing it.




EDIT: Wait.... ****. My old NA harness is an automatic harness. That's more work....

 

Ohhhh. And we just got the engine turning over with the JDM engine harness about 10 minutes ago. It didn't start, I think it is some one the ECU pins???


My brother is the electrical guru..... I'm stumped!


If I used the NA harness, I wouldn't have to change any of the pins. Correct?

 

I used my n/a harness on the the jspec motor. It runs fine but I think I mixed the injector wires..... I did block off everything, and since I had an s4 vert and the motor was an s5 I changed the injector plugs... and also removed the vac rack, so the only **** that wasnt an s4 was the injectors(square plugs vs. round). The oil pressure and water temp are the same ****....

 

ON s5 cars, the NA harness is very similar to the turbo harness...the VDI solenoid wires can be used to carry knock sensor signal, I believe...refer to the differences in the s5 FSM. ON s4 cars, the harnesses are more significantly different.

There is no difference in automatic or manual engine harnesses, for fc's. The difference lies on the drivers side harness.

Oh, btw...an engine will TURN without an engine harness connected at all. Hell, it'll TURN with a starter and trans bolted to it on the floor, so don't congratulate yourself, you havent done anything yet

 

The drives side harness? You mean the huge one that runs from the interior, out threw the fire wall, and around the front of the car?



Yeah, but everything was hooked up, and it should have started. I missed something somwere I guess.... Seems like it's not getting spark.


But I was happy to hear the compression pulse's when it turned over! Sounded like someone shooting a CO2 gun out the down pipe.

 

YOU have probably blown a fuse when you put the JDM harness in the car and applied power. The stock n/a harness should have worked just fine especially since you don't have either the VDI or the Six Port solenoids connected (the harness plug to each is off each).

If the fuses in the engine bay are good...then check the ENGINE fuse in the crew compartment.

Series four and series five na harness work just fine in a turbo. Only minor corrections need be made. READ my first three posts on this thread.

 

ON a series 4, the BAC valve lead, secondary injector leads, 02 sensor lead, TPS lead, are all too short and must be modified to work. Also there is no knock sensor lead, nor is there a wire run that can be used to carry that signal, so you must run your own in that case.

 

Everyone has their own take on how to do the mod your all up in. I been doing the rotary thing for like 5+ years now so I'll offer you what I can. Whenever me and the buddies have done a turbo swap into a non turbo car I have found it works very well for us to use the non-turbo ecu and harness. All using the turbo ecu would do is add sensors that would make it harder to make power like the boost cut off feature. I understand your trying to put 2 harnesses together and I'm not answering your ? on doing that. Just wanted to let you know that using a non-turbo electrical side is an option. No you won't blow your motor, yes you can put in a fuel pressure regulator to put your mind at ease. And yes you can turn your boost up to the sky and blow it up if you like. Good luck with your project. Have fun!!!

 

It's just wire. It's not a big deal. And not much wire at that. Been there, done that. If I can do it, anybody can.

 

The harness is one thing, but the ecu? C'mon now...it has no timing retard under boost, and probably much less fuel on the top end/above atmospheric (seeing as how it wasnt designed to go that high). What about the NA pressure sensor which is not calibrated for higher than atmospheric pressure...and what about the NA afm which doesnt read quite as high as the turbo unit? Why do it half-assed, it's just a couple hundred bucks more worth of ecu/harness to buy, why take chances with your hard earned money and time invested into your project because you want to cut corners?

The point is, it's already been done for you. Harnesses can be had for 100 bucks all day long, why fool around with wire runs and cutting/splicing stuff, we have enough problems with connectivity anyway. I just don't see the point in trying to be a cheap-***...it'll always come back around to bite you.

 

i have an NA wiring harness in my turboII conversion. just use the na VDI wire for the knock sensor and everything works fine. its the same pin on the harness plug but its the wire for the VDI solenoid on the NA ECU, its the knock sensor wire for the TII ecu.