Quote Originally Posted by TDCRacing View Post
OK SO.....

The conditions:

69*F ambient temps (according to the digital cc)
IAT sensor removed from the intake tubing
IAT temps were at a steady 85*F for at least 10 sec before test was done
Test was done with a glass of ice water (32*F)

THE TEST:

With car turned off and key in the run position and the hpt scanner right in front of me and the IAT readings being a steady 85* for at least 10 seconds i submerged half of the sensor in whe cup of ice water ( not up to the actual connector even though it is sealed tight ) and the IAT temps on the gauge instantly started going down in at least 8 deg decreasements and took aprox. 16 seconds to reach 35* and stayed there contiunesly even at 35 seconds.At that time i stopped counting.Test was over.


OK well this is a 50 degree difference in temps. A 50 degree drop in temps is easily seen if you have an under hood open cone and have been stopped for any short period of time and then start driving again.This is not to say that the air that the IAT sensor is reading is not the temp that is being shown but rather a delayed measurement instead.



I dont think that there is a way to tell if the IAT sensor reacts quicker/slower to a majior temp change compared to a minor temp change.I would think that it's reaction time would be the same.


So yes the IAT sensor is delayed in reading the actual temps that are present.

Now a question: Could this delay purposely be made like this because the pcm would not be quick enogh to make instant changes like that? ex. to compensate for timng ect due to the cooler air temps.....

Just a thought
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