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CLT sensor erroneous reading in 3.83

Posted: Mon May 06, 2013 9:36 am
by UJM
This is my first post here, but I have a lot of forum experience. I was formerly on the MS Extra forum since I had to find an email address to use to get in this one.

Here is my setup:
MS V3 on a 1981 Suzuki GS1000, which is an air cooled 4 cylinder 4 stroke motorcycle. I am running version 3.83.
The bike has 2001 GSX600 throttle bodies & injectors.
CLT sensor is a thermistor mounted in a ring terminal and bolted to a chunk of aluminum that is between the fins on the back side of the head. It and the IAT sensor were calibrated in Tuner Studio using the 3 point entry and 2490 offset values. I have table data for each thermistor and entered the value for three points: 0 degrees C, a mid-range value, and the top value. For CLT, this was 0, 150, and 300 degrees C.
IAT sensor is a thermistor mounted in the airbox.
O2 is a Bosch WB controlled by a BPSX controller, which outputs AFR 9 at 0V and AFR 19 at 5V.
MAP sensor is a GM 1-bar.
TPS is the GSX sensor calibrated via Tuner Studio.

The bike won't start, but in this post, I want to try to figure out why mt CLT reading is constantly like -32 degrees F. It worked properly in v. 3.77 and also when I tried the MS Extra firmware, but in version 3.83 it is flaky. I have done the three point calibration repeatedly with no effect.

I'll attach a MSQ file for reference.

Re: CLT sensor erroneous reading in 3.83

Posted: Mon May 06, 2013 5:14 pm
by UJM
I have tried reducing the maximum temperature point from 300 c to 250 and 200 and get the same result.

Re: CLT sensor erroneous reading in 3.83

Posted: Tue May 07, 2013 1:20 pm
by UJM
A friend pointed out this thread in a Porsche 914 forum where CLT sensor values were a problem due to the air cooled engines. I'm looking at the ini file for 3.83 (megasquirt-II_3830.ini) and am going to add "set EXPANDED_CLT_TEMP" to the beginning of it so as to allow the higher coolant temp values generated by the air cooled engine.

UPDATE
This made no difference, so I reloaded v. 3.78 and the CLT sensor works properly again.