I just picked up a 1989 widebody convertable with an s4 TII engine in it... has a few parts missing (turbo, throttle body, injectors, ecu, etc) but I've got lots of parts around so I am sure I can make it go.

All I want to know is what I need to do to make an S4 TII ecu/harness work in an s5 N/A car, so the gauges, coils, etc, all work, with the S4 TII engine. I've got s4 coils around I think, I have all the s4 electronics AFIAK (afm, pressure sensor, etc).

I have a knock control unit around somewhere but I don't know if I can find it anymore! is it needed to make the engine work? It obviously can't do much since I've broken lots of motors from knock lol.

 

bump since I'm off the SECOND page allready!
someone's gotta know something about this...

The ECU hooks to the car as well as the engine, I'm sure.. is this plug the same on S5's as it is on s4's, and my s4 ecu will just "plug and play"? or what?

 

Nope, your supposed to stay in series. I'm doing a s4 n/a -> s5 t2 swap and I just found this out also. Pretty much I'm just going to bite the bullet and buy a haltech to make the swap work. GL

 

bump!

what do I need to do to make my s4 TII ecu work with my s4 TII engine - in my s5 vert?

 

Easy. Get the wiring diagrams for a series four and the wiring diagrams for a series five. Since you know (I'm sure you do), that the plugs on a series four EMISSIONS harness do not match a series five FRONT harness, you'll have to make adjustments. So you look at the two seperate schematics and figure out which wires to move where and how to do it.

See the FSM for what a EMISSIONS harness consists of and what a FRONT harness consists of and maybe throw in what a ENGINE harness consists of. They sure as Hell are not what is thrown around on this and that other forum.

Even better, pull the EMISSION harness out of the series four and lay it along side the series five EMISSIONS harness. Walla! The plugs that are not going to the ECU are , well different with different wires in different sockets going to different places. But it's doable if you look at the schematics. Several people on this forum have done it. The CZECH guy and , sorry forgot the name, another guy on this forum.

 

A little looking around this site I come upon this: https://www.rx7club.com/forum/showth...ghlight=fem-01

Now the guy you want to listen to is Luciu$ down near the bottom of the thread. What he writes in several posts might not make sense unless your staring at the wiring diagrams, which he is assuming your looking at.

 

thanks HAILERS!
that guy is doing hte opposite of what I want to do though, he's putting an s5 engine in an s4..

basically, what I want to know is what needs to be done to make an s4 ecu work in an s5 chassis, powering an s4 engine.

edit
oh, I read the thread lol...

gah, this looks like I'm getting in over my head!

 

The series four EMISSIONS harness has two dark yellow plugs on it that do not go to the ECU. They mate with the FRONT harness. The problem is the series five FRONT harness plugs and wires DO NOT match the series four EMISSIONS harness your putting in the car. You'd have to stare at the schematics for the series four and series five and make changes to wire locations etc. Very time comsuming since you need to find out what wire does what in life and goes just where.

It's doable but it won't happen overnight. I doubt you'll get anybody thats done it to desribe exactly what wire goes where and what adjustments need to be made to the two harnesses. Maybe you'll get lucky and someone that's done it will reply. At least this will get you to the top again.

 

I think...

that it's time for me to find an s5 TII ecu / harness (will s5 na harness work?) and s5 TII afm (will s5 NA afm work?) I have an s5 NA afm and harness (came with the car, in the trunk)

I have s5 TII intake manifolds/mop and etc around here somewhere as well I'm sure, injectors and etc. too.

Maybe that is the better route to go.

or megasquirt.

gah! I thought this was going to be a mostly plug-and-play affair

 

Tell you what. I only own series four. I've never touched a series five. But, that said, I put a series four turboII in a non turbo car using the non turbo harness with small changes to the wiring. I see no reason a series five non turbo harness won't work with some minor changes. I'm sure it's good enough for getting the engine/car up and running until you can get a series five ECU/boost sensor/afm. Just my opinion.

I'd give a more precise answer but I don't own series five schematics except the ones I downloaded from alldata.com. I might take a look out of curiosity.

I mean how difficult can this be? All series five harness and an engine that is similar to the series five. Four fuel injectors, a boost/pressure sensor, afm. Oooops.
the series five is looking for the omp for a series five. Runs like a dog without the electrical omp. But if you had a series five omp you could just hang it in the engine bay with the electrical plug on it and not connected to the engine. And use the series four mechanical pump.

Just something to think about.

 

I have an s5 pump around here somewhere.

This is my first S5 car, but I've pretty much JUST used s5 TII engines in my 10AE (more gooder!)

I looked around for an s5 FSM online, can't find one I have 2 s4 FSM's, and they're so fantastic

wish this was an s4 with s5 tails oh well.

I think I've got all the s5 parts I need to get it running - except ecu, harness, afm, pressure sensor.. basically all the mechanicals and none of the electricals.

I had a look under the dash today in this car and it's a nightmare, non-stock wires everywhere doing who knows what!

So, since I'm going to have to deal with that anyways, I guess I'll go back to the origional plan, and use all the s4 electronics that I allready have, and just figure out how to make the s4 ECU play with the s5 car.

rewiring a few of those FEM car thingers doesn't sound so bad anymore