Hello guys,

I was searching through the forum for an answer but the only threads I found didn't apply to my problem, the only one the guy said that his harness was actually a turbo one.

The issue I have is "simple".

I have an early FC that used a FB GSL-SE ecu, engine and engine harness from factory in Europe. Since that engine is in need of a repair, I sourced a S4 GTU engine with manifolds and rats nest from the US. I'm trying to get it working but since the normal S4 N/A engine uses coil packs and not a distributor, I had to source the engine eletronics. I have a S4 N/A ECU (N322) and I have available a S5 N/A engine harness with the S5 rats nest. Can I make the S5 N/A harness work with the S4 engine and ECU? If so, anyone know more or less what I need to do to make it work?

Thank you

 

Before you go for the Parts Cannon, hold up for a minute so we can straighten a few things out. I'm reasonably aware that your car uses the N323 ECU from the factory. It is not a GSL-SE, that is N304. They are similar in the ignition system, but the rest of the ECU and Harness are completely different from your N323 setup.

The European spec S4 Turbo ECU is N340, I believe it's a revised N33x (North American S4 Turbo). European market S5's are all turbocharged, with the N380 ECU. I do not have specific details yet, but I believe it is a further revision of the North American N370 ECU.

N323 is closest to N326, the major difference is the Distributor vs Crank Angle Sensor that controls the ignition system. I think you are making more work for yourself than what is necessary by trying to mix and match parts. The simplest solution that I can come up with is to transfer manifolds and accessories from your N323 engine to the GTU one. Unfortunately, I do not have a European-spec Workshop Manual to compare to the North American manual to pin down differences and recommend solutions for. If it were a Japanese-spec car, I could easily sort through it as I read Japanese.

If you have access to a European manual and could scan it, I would be more able to guide you on a proper solution to this.

 

Thank you for the reply.

The car it's a N/A FC from 1986 from Europe (distributor instead of CAS, thermal reactor exhaust instead of cats, aux port valves are butterfly valves). I actually didn't see the ECU reference yet, so I cannot confirm it, but I was told the ECU is similar to North American GSL-SE, fuel only with a seperate box to control ignition cut for thermal reactor.

What I got to swap in is a complete '88 GTU engine (also N/A) and I also have a spare S4 European N/A ECU (N322), that I initially thought I could use. I want to take advantage of the coils and overall better/more modern fuel control, unfortunately, finding a harness has been quite difficult. Since the rest of the car is supposedly a normal FC, I thought the swap was going to be easier thanit is. Since this country's customs are very rigid I have to source parts locally. Unfortunately, I was only able to find a S5 turbo wiring harness from an UK car so far.

Also I searched some more and found out there's two people that posted in the forum about similar equipped cars and they said their cars had an ecu with the same connectors as a normal S4 (both were a N368 with S4 plugs, only controlling the fuel injection, but their cars were sold in '91 with S5 bodies and mine is a S4 from '86 so, best case scenario, I'll have a normal S4 ECU under the dash?).


I was searching for some euro wiring diagrams and manuals before I started this thread and I'm still searching for them as we speak. I already have found some for the "normal" Euro FC, but nothing for this early Mazda contraption.

 

So I did some digging and found an early FC (October 1985, so series 4) Wiring Diagram book in Germany for 30 Euro. PM'ed you a link and some info on digging stuff up from our Deutschland friends.