Hi guys,

Alright, so brace yourselves, I am going to say some hard hitting things here. I am uninstalling my turbo set up!

Before you unleash hell on me let me just say. I bought the car as is thinking it was the my ideal car, then i realized it didn't feel like my car as I hadn't done any work on it nor made it my own. Basically, its much easier to sell as a stock standard car and a turbo kit with some extras.
Don't worry, I'll be buying a different mx5, probably an NA8 and building it from the ground up myself, exactly the way I want.

I'd like to clarify the process before i go unbolting parts ***** nilly.

Unbolt intercooler set up
Remove turbo, plugging oil drain ports
Replace turbo manifold with stock headers (connected to stock exhaust)
Reinstall MAF with filter, etc
Unbolt COP kit and replace injectors with stock ones, then reinstall stock coils and bracket
Unplug MS2 PNP and plug in stock ecu (shouldn't need to mess around with wiring as its a PNP right?

This is the process in its basic form correct? Are there any pitfalls need to watch out for or handy hints that would make for a simple night?
Before starting the car for the first time after the job, what should i double check to avoid catastrophe.

I've attached photos of the current set up.

Cheers, Max

 

I would suggest selling the car as is. Taking it back to stock may not be as simple as you list if you didn't perform all the work to get it to this point. Some stock wiring may not exist anymore looking at these photos.
The first thing that jumps out to me is that it is a 1.6, and the thermal fan switch on the front water neck is missing. That controls when the radiator fan kicks on. With the MS2 it isn't needed because the coolant temp sensor on the back of the head is used to determine when the fans should kick on.
Secondly, that is not using the stock coil packs. Those will probably not work with the stock ECU as dead times and such are different.
Is that that a variable throttle position sensor? Looks stock but I thought they had a Bosch sticker on them.
Looks like it has A/C compressor but no A/C fan?

 

As far as I know its the standard throttle sensor.

It has had a coolant reroute as well which also complicated things. A switch i can find for cheap at a wrecker so bolting that back on "should" be straightforward.

I'll be using stock coils i picked up from a wrecker.

I've also got the a/c fan in the garage, just need the time to install it again so no issues there.

Do you know what the clear plastic cylinder is? It has clear tubes running in and out and looks like a small filter for something.

 

Coolant reroute shouldn't hurt anything, it's the wiring that might be a nightmare.
I couldn't figure that clear tube either, it looks like some sort of check valve or filter. It looks like it goes through the firewall? Is it connected to the MAP sensor on the MS2? I wonder if its some sort of pulse dampener? Try and figure out where it actually connects.

 

Fingers crossed everything is there and kinda just plugs back in!

I'll have a proper look over the weekend at where it ends up and start the process.

When attempting to start the car, what am i risking if I've have missed something? I'm not completely clueless in terms of mechanics but I'd like to not break anything because I was unaware of a small issue.

 

Did the car originally come with AFM? You should also know how the fuel pump is currently being controlled. Typically for 90-93 1.6 US cars we jump a couple wires where the AFM was and let the ECU control the fuel pump.

 

Yep it came with an AFM, known as a MAF sensor here in Aus. That'll be a simple part (touches wood)

 

ok, well good luck!

 

I forgot to mention that if you go back to the stock ECU you will probably need to install the ST SIGN fuse again.

 

why dont you just fix the janky parts/ assembly of this build? that would make it your own. Otherwise, this whole plan is silly IMO. take apart, deal with lots of unknowns, deal with selling etc... just to do it all over again in reverse?

The fact that you consider this an option, makes me think you WILL NOT FINISH ANOTHER BUILD. If you dont have the motivation to make changes, to put ownership into the car, you sure as hell wont do it from square 1.

I can count a good list of ugly parts in that engine bay. to fix all that will be some effort on your end and make it 100% less pooey.

* front water neck delete
* radiator hose- make a nice aluminum unit
* replace all of the worm clamps with legit stuff- Oteiker clamps
* fix that hideous pipe from the filer to turbo
* remove the oil feeding valve cover hose from the turbo inlet
*get rid of the fish tank air hose, ewww


I could go on, but you get the point. MAKE it yours. quit using someone elses **** as a reason to dump it.

 

Inline fuel filter being used as a pulse damper. It will be in the line from the manifold to the onboard MAP sensor in your aftermarket ECU. Leave it there. Make sure the MAP signal is taken from the back of the manifold. It's it's near the throttle body you'll get spurious readings.
Only really need a pulse damper on an NA6 with a non VTPS as that ECU will run MAP-DOT for accel fueling. Tricky to tune those thresholds with a noisy MAP signal. If it's an NA8 or later TPS, then you don't really need the filter. Just relocate the hose to a bung at the back of the manifold near the firewall.

Didn't read any of the rest of the thread because I'm lazy. Sorry if that's covered.

Oh and, where are you?

 

I believe he's in Australia.