02-05-2011, 12:50 PM
Join Date: Aug 2006
Location: Cedar City, UT
Total Cats: 4
Temp sensors fustration
My car has "never" had the sensors temp match.
Car sits for days, is there any reason why the water and AIT should always be 2-30 degrees difference from each other?
Air temp here in Utah was 0 earlyier this week as per local airport. Car water temp after sitting for over 12 hours was 54 before cranking, and air temp shows 20, with sensor in and out of intake tract. mercury thermomiter showed close to 0 as well when i checked
The AIT is the GM one, and i tested all four of the ones i have, they all showed same exact temp in TS, and default to -40 when unpluged
The physical water thermostat, it is a 180*, and i figure it opens slowly close to that, as the water temp will spike to 200-203F before it fully opens and it drops back to around the high 170s before stablizing in the current cold weather around 185. (It does NOT have that 1/8th hole drilled in it to let a bit of water flow when it is closed, i do not see how that can be an issue for when the car has been sitting for days though and has not been cranked yet)
I have pulled the water temp sensor out before and carried (close to) boiling water from apartment to car, and read 98 Celesius (changed it so i could look for 100 exactly instead of 2XX and was spot on compared to mercury thermomiter i had clipped to the pot as well) on both the water and AIT sensor.
Because of this, i figure the upper temp range is accurate, but the lower temps are total crap.
For water system, this is not as important, but with AIT, im thinking it is giving me issues due to how cold it is here. many people seem to see 10-20 degrees above ambiant, mine seems to very from 20-60 above ambiant. Sensor is mounted in exit of intercooler, so should be getting little to no heat soak when running, but should not be a factor when the car has not been started either
I use tuner studio, so is there some way to get the voltages on the water and IAT temp in that, so i can figure out current air temp, since it is blow freezing here, and then rescale my files so when i reburn my firmware it will give me more accurate readings?
Currently i am using HR11, and using HR10 and the standard code, there is no tempiture difference after buring firmware and turning car on ( no cranking between buring different firmware)
It is a MSPNP, and it is using all the files that came off the DIY website for the 97 Miata
I had a 93 miata with its version of the MSPNP, and it always worked from day one. This one has never seemed to be right ever