CLT reading low. Cruising 140-150, boils coolant at 200
 

So after many difficulties of getting the car to run (Dimitris is very helpful, it was in the fault of the previous guy who worked on my car)

Anyway, I got the car running, and everything seems fine, but while I'm cruising, I'm running at around 140-150 F which is way too low. It was boiling at 200F and I had the shut the car off.

It's a VVT swap stock into NA miata. Running settings from DIYautotune and the setup for thermistor settings are:

bias res 2490
14F (-10C): 9250
71.6F (22C): 2320
176F: (80C): 330

Am I even supposed to follow diyautotune's values? Dimitris sent me an ini file and I felt like I shouldn't need to add those values anymore. I tested the coolant temp sensor and it's reading the right resistance values.

Is it possible that Dimitri used a different bias resistor in his ECU? What does the INI file from Dimitri say in it? It should be text so look for anything in it that specifies CLT...

When you first turn the car on BEFORE starting it, what is the CLT temperature as indicated in tunerstudio?

I searched the ini and there's a lot of clt entries but they don't make any sense to me. If dimitris is okay with me posting the ini then I can upload it. I haven't checked the clt temp at cold temp but I'll check tomorrow

Which one of his units do you have? A diypnp enhanced?

Ms3 basic

and calibrating it to RX7 CLT (S4 & S5) isn't close?

Haven't tried. Just ripped my sensor in 2 pieces. Need to go get it and try it again haha. I will be back.

Update: new sensor. Using rx7 (s4/5) Still cruises at 140-150.

Water sensor temp just slighter lower (about 5 degrees) than iat sensor. This is from readings right after I install before starting car

What does it read after the car has been sitting all night?

5 degrees lower?

Try adjusting bias resistor use and down just to see if you can get it to match when cold. Write that number down.

You need to talk to the guy who built your board.

Also, you need to find out what resistor on your board is the bias resistor for coolant and meter it. Use that value in your calibrations.

Serial number?

Basic ms3
94-95
11405

The bias resistor value is 2490 for all my ECUs.

Check the temperature on a cold start, it should be very close to the IAT and the actual ambient temp.

does OP have some "racer" reroute?

nope. oem config for now.

Everything cooled down, coolant reading 68 f and mat 73 f

Could it be an mechanical issue?

Thermistor table reads

Rx7 (s4/5)
-4f 16200
68f 2500
176f 300

Bias resistor 2490

Where are you located Matt?

Vancouver BC lol don't think it's anywhere close to you guys :\

sounds like it's calibrated correctly.

Found out my thermostat opens at 68C = 154F. Time to get the oem one.

Still doesn't explain why it's boiling at 200F.. hmm

how do you know it's boiling, and how do you know it's boiling at 200°F?

It was making boiling sound at 200f and I can hear it bubbling from inside the car.

i pulled the iat and clt sensors and left it in open air. The clt was at 64f when my iat reads 70f.

I had an issue earlier with prosport gauge accuracy so I sent it back. They told me it's accurate and I also tested it in boiling water. The gauge does read 212f. However the clt reads at 165 when the prosport reads 188.