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ECT inaccuracy since change NTC change

Posted: Sun Feb 24, 2019 1:57 am
by Kaldek
Since UTCOMP v3.5 and the introduction of "simplified" calibration of NTC sensors, I find that my ECT is now less accurate and the temperature tends to swing wildly (up to 10 degrees C). My sensor taps the ECT sensor feed going to the ECU from the 3-wire 5 volt referenced engine coolant temperature sensor.

I calibrated the sensor from ambient (cold engine) to operating temperature (82C) according to the data from my engine data logger (EvoScan).

Data in EvoScan might show a steady 85 degrees, however the ECT reading in UTCOMP will swing wildly from, say, 77C to 88C over a period of a couple of seconds.

Can I get some guidance on better calibrating the R25 and Beta values, or perhaps a smoothing algorithm in UTCOMP v3.8 for NTC sensors to cater for the inaccuracies caused by the introduction of the simplified method?

Re: ECT inaccuracy since change NTC change

Posted: Mon Feb 25, 2019 10:22 am
by ArT
Hi Kaldek,

Could you send me your settings file before update and after update? And your voltage/temp table. I'll check it.

BR
Artur

Re: ECT inaccuracy since change NTC change

Posted: Sat Mar 02, 2019 6:40 am
by Kaldek
ArT wrote:Could you send me your settings file before update and after update? And your voltage/temp table. I'll check it.


Hi Artur, it turns out this was my fault. I had installed a bad radiator cap which caused an air pocket to be trapped in the system and cause inconsistent cooling, which explains the massive temperature swings.

I have replaced the radiator cap, correctly burped the coolant, and it has resolved the problem.

Re: ECT inaccuracy since change NTC change

Posted: Mon Mar 04, 2019 1:29 pm
by ArT
Uffff ;)
Thanks for info.