Most people and writeups recommend using the S4 sensors and whatnot and retaining the S4 harness and ECU and plugging them into the S5 motor. However, I have a complete S5 parts car that my motor came from.

So can I install the S5 motor, using its engine harness and ECU/etc. into my S4? Is there any problems that would be encountered?

Thanks,
-Jayson

 

I foresee this thread being closed because of the irritation it causes the rotor Gods.

I did what you did but I swapped out the s4 into an s5.

Problems encountered?

Um, this is an rx7 you're talking about right?

You will not be able to use the s5 ECU to the s4 harness. Or vise versa.

Plus you have an OMP issue to deal with. The s4's are mechanically driven and the s5's are electric.

The EGR and emissions rack is different also.

tick tick tick.......

Thread will close soon.

 

Yes, I know, the search ****'s. As I said though, I will use the complete S5 motor, ECU, and harness. As such, I do not foresee the MOP issue nor the others. Worst case I would anti-emission it.

I *think* everything should be ok...I just want to post and see if someone comes up with that one thing I forgot that would cause a headache.

-Jayson

 

Ripping part the front half of the car, ecspecially the dash. Really it is not worth it, I have thought about it quite a bit, but decided just to swap the block, manifolds, etc...

 

Why? Are you saying the chassis harness needs to be replaced as well?

 

Yes Jayson, you have 3 options here.

1) you swap over all the s4 sensors and wiring and make the car think it still has an s4 motor. A lot of work, but will provide the most seamless running engine in the end.

2) you take the s5 engine and ECU, and cut/splice the s4 chassis/dash harness to plug into the s5 ecu and engie harness. Easiest option as far as work, but will result in a lot of headaches and a crapass running engine.

3) you take every wire, the main harness and all, out of the s5 and put into the s4 car, making it an s5 with a body swap. This will provide a good running setup, but is WAY too much work for no real gain.

 

Do you know of a write of How to do it? Because I have been reading if you are going to swap a s5 in a s4 it is better to just trash the emissions, but i need them.

 

There is no writeup because it is not an accepted way to make it work. IT is second only to putting a v8 or something in your car...you just dont wanna do it...but it can technically be done.

There are s5-->s5-->s4 swap writeups on my website, www.rotaryresurrection.com

 

Why is it not accepted? I think it would be better than just swapping the parts over, isn't that sort of half-assed?

Why wouldn't you wanna do it? Wouldn't it make it easier than swaping the parts? All you gotta do is get the S5 engine harness, ecu, maf, and splice away! The dash harness that is....

 

Yeah, sure thing...let's all go hacking up our cars' wiring, and sprain a muscle or 2 patting ourselves on the back for the great job we did.

Engines come and go, but you only get one car...

 

uh, all this talk about swapping

it gives me a headache that I am more than willing to deal with cafc

At this stage of the game all I can offer you is:

Tell me what, specifically, you want me to inspect regarding the diferneces between each series.

I have everything for s4. manifolds... relays....injectors... injector lines etc etc etc....you should see my parts rack.

Especially the dash hanging on my wall, only becase I was sacered to replace the dash in my 86 with it because aftter taking it apart, I thought to myself..
'Nothing electrical will ever work again" if I swap out the dashes. Even if I did swap it correctly, the dash would probably rattle upon acceleraions or idle.

But anyway

We'll take it point by point. pic by pic

easy cause my 91 motor is sitting on my garAge floor
waiting for my mazdatrix rebuild package which should be any day now...

But I need you to supply the specifics.

I have three fc's. One stripped gxl.....this motor is now in a 91, and I also have an 86 that is very mad at me right now....

Lets get down to bidness.....how can I help? I got the digitalous (digital camera)

 

I just see it as being easier to resolder some wires than tearing down 2 blocks and hoping everything matches up and works correctly. Because if there is say a mechanical problem, you pretty much gotta check everthing, because of adding those S5 parts.

Yeah BOTH are a lot of work, but (imho) it seems like splicing/solder the wires would be easier.

 

Ok, the situation is this:

I have an 88 vert, dead motor.

I have a motor out of an 89 GXL parts car, 15k on Mazda reman, new clutch, all in all, a great motor. When I pulled it from the car, I pulled it with everything. It still has all of its accessories, harness, ECU, hell, it even still has the oil cooler sitting on top of it.

What I wanted to do was swap this entire engine in, with computer and all. Barring that, I will use this engine and convert all the sensors over to the S4 stuff, per Kevin's writeup.

 

i agree with every body its lots of work because u hav to change all the harrness in the engine bay

 

so to put a s5 motor into a s4 ur gonna basically need the s5 ecu, wiring harness, and intake manifolds? as far as the omp goes i can just use the mechanical one off of the s4 if i swap front covers?

 

I'm dropping in a S5 Jspec into my 88 GTU. I am swapping electronics on mine.

I have to swap the Throttle bodies/and TPS(S5 is dual)
The Injectors are oval shaped on S5's so I got the S4 squares.

The EGR is also Oval I think on S5's.

Other than the front plate being swapped to S4 with Mech OMP that's the main problems I have come across.

I'm not going to deal with emissions because it's a Jspec so it doesn't have an emission spot on the intake manifold and I don't have to pass for 2 years.

Anyone know the differences for the Emissions stuff?Anyway to get a S5 engine to pass in S4?