89 jdm vert
 

I need to fix my engine as it's passing combustion gases into the cooling system.

Two main questions:
how do I know if my car is S4 or S5?
where can I buy JDM parts? I know there are some differences.

well of course it is JDM, but do you mean JSPEC? if so why do you think it is a JSPEC? does it have a factory turbo engine?

and specifically what parts? your post is as vague as vague can be.

My car is right hand drive and it just came from Japan. I already learned (the hard way) there are some differences. Just need a parts supplier that understands those differences and can supply quality parts. I will be rebuilding the engine very soon.

I thought my car was S5 but started wondering if that is accurate when someone told s4 and S5 have different thermostats housings. Left me wondering...

if your thermostat housing is plastic then it's an S5, as far as parts, there are few parts that are different that you might need during a rebuild and none of them are things you'd probably break unless you actually tried. so no, there is nothing special you need to specifically worry about.

Yup, when it comes to the rebuild "kit" itself, it doesn't matter much on series

But, if i may make a suggestion, tear the engine apart FIRST, THEN order what you need

and there is a place not far east of you that has some experience with them.

Does it make a difference where I purchase the parts for the rebuild? I know I had purchased a water pump housing gasket and it ended up being the wrong one.

BTW- where east of me is this place?

you've been talking to him most of this thread lol

At this point I'm convinced the car is S4 as it is an early 89. The engine is now out of the car and in pieces. Currently the housings and irons are receiving attention and my parts are on their way from Mazdaspeed/Mazda Motorsport.

I'm still trying to sort out one detail and that is the ECU chip. RTek's chip will not work on my ECU as it isn't compatible with JDMs. I understand Pan Speed makes some JDM compatible chip but I'm still unsure if the one I found will work on my N341 ECU. Does anyone know if ECUs are specific to transmission types?

no, the transmissions aren't computer controlled in these like newer cars, they run off vacuum