Did you install a re route with an aluminum spacer in the back, with a gasket on each side? Did you add a ground strap to the spacer? The sensor will gI've a crummy signal if you dont.

Would the ground wire be as simple as cutting the ground wire to the sensor, crimping a ring terminal on it, and bolting it up?

maybe, but that sounds more difficult than just tapping a small hole and making a small jumper to the head.

I'll order an OBD reader on amazon.
Not sure what Yossi is talking about. There are no codes. The only issue is the coolant temp gauge reading low with highway driving. It was about normal in the city when it was warm out from what my friend and I saw.

No reroute yet, was thinking of doing that with the turbo install.

Not for the codes, but for a digital reading of the temperature.
You know what to expect from a stock ecu every time.
MS can have all sorts of weird untuned warmup and idle variables.
In my case with the reroute, it will read for a minute or two, then shutdown and drop to nil. My lazy ass wouldn't care.

Thermos can stick open or closed depending on type and failure mode. Driving slowly the water pump doesn't circulate water as fast as hwy driving, if you get what im sayin'.

Isn't the water pump circulation a function of RPM? Air flow on the highway can make up for lower revs, no?

The needle moves. It goes up to about halfway when I'm driving around town in a high-ish gear.

I'll order the obd reader on prime today and drive with it in before swapping over. Might just use torque or whatnot. I can use the obd reader in my other car in the future so it's money well spent.

Wouldn't the needle just stay put and not move if the thermos was stuck closed or open?

No. NB has 3 pins on the sensor.

Signal and ground drive a signal to the ECU. This will read correctly either way.

Third pin drives the temp gauge and relies on the engine ground for proper operation. This is separate from the ECU signal ground. That is the one that might need fixing.

Okay so I need to check the ground to the engine? I don't think we took one off, but it's not hard to double check.

It got to about midway in town but this is on the highway.

https://cimg0.ibsrv.net/gimg/www.mia...080b66e6e6.jpg

Me thinks your thermostat is stuck open. Highway air flow reduces temperatures.

Ahh bollocks, I don't want to drain the coolant a third time haha.

Worth trying to do the coolant reroute with the engine in? I might as well just do it if I'm replacing the thermostat...

Yes pump flow is rpm dependent, but average rpm over a given time span is dependent on vehicle speed assuming you are using the right gears in a manual car(especially in a Miata that likes ~4krpm on the hwy almost all the time).

As mentioned, make sure this isn't an electrical issue first, but I agree it sounds like thermo is stuck open.

I did mine with the engine still in. I didn't think it was too bad, just annoying.
It helps when you have hands like Trump. :bigtu:

Cleaning off the old gasket was the most difficult part of putting in re-route for me.

Got the shit today. I'll just do it and stop being a bitch.

Leaving the reroute for when the engine's pulled because that makes sense.

Stupid thing was stuck on itself. I was able to push it back on itself and get it to the point where it would probably be functional, but I bought another one and gasket for 10 bucks so whatever. The one I have is the autozone one with dual domes. Should be fine for the next few months.

I have a stant superstat I got with my reroute kit. I saw something that joe perez did ages ago comparing the size of the opening. Was this an issue at all? Do people prefer just using a regular stant or napa one with the larger opening for the reroute?

Alright, few updates in the last couple of weeks!
I'm really new to wiring and stuff, so I wanted to take my time and make sure that I didn't screw anything up with the megasquirt. Took the opportunity to wire in the boost gauge too and have it running off the back of the manifold. I put the vacuum line for the megasquirt where braineack's instructions told me to, teed off the FPR and in through the passenger side firewall. Good god it was annoying as heck to find the line in the passenger footwell. Routing it through to the drivers side was pretty ridiculous too. With @bytevenom's help, I ended up pushing through a coat hanger from the driver to passenger's side, zip tying it to the vac line, and then pulling it through.

A few random pictures...



https://cimg1.ibsrv.net/gimg/www.mia...a16dc22090.jpg
Started getting the wiring for the boost and AFR gauge in. I also have an oil temp/pressure sensor that needs to go in, but I'll do that when the turbo goes in.
https://cimg3.ibsrv.net/gimg/www.mia...b19abf66d3.jpg
So close to having the wiring doneeee... I may have burned the butt connectors a little bit. Should have heat shrunk them too. I might splice that in later, but it seems superfluous.

https://cimg5.ibsrv.net/gimg/www.mia...7884c38235.jpg
https://cimg7.ibsrv.net/gimg/www.mia...d31e252b85.jpg
The two pictures above are the rats nest I found behind the radio. It looks like the splices were made and electrical tape was used to seal the deal. I'm on the fence about whether I want to take everything apart to try to fix it or just leave it be because it's clearly been this way for years without issue.

https://cimg8.ibsrv.net/gimg/www.mia...2b32da7923.jpg

As a side note... I bought NB2 seats. Except that when I say that I bought them, I mean I gave my cousin money to buy them for me. Said cousin lives in Virginia. I wonder when I'll actually get them lol.

why two widebands??