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The coolant mod gets rid of the coolant passage on the IAC housing of the throttle body. Cars that were run in the winter in the northern States and Canada might have needed it to help eliminate icing of the T body in very cold temps. The hot coolant flow to the throttle body IAC housing eliminated this possibility but since most owners never drive their car in the winter it's not needed. You can just remove the two hoses that go to the IAC housing and join them together. The hose "pipes" are still attached to the IAC housing on the T body but not used. To go a step farther and for a better look you can carefully shave the whole coolant passage from the housing. Eliminating the hot coolant flow thru the t body is also better for performance.
The last picture is a bottom view of the t body and shows that the whole coolant passage has been removed.
The throttle body has bronze bushings installed as well. If you are having trouble maintaining a steady low idle rpm then there is a high probability that the throttle shaft housing is worn and allowing air to enter where it's not supposed to thus screwing with the IACs ability to provide/control the correct idle rpm. Another symptom is if you have to blip the throttle sometimes to get it to return to a proper idle speed.
As a final note......the only difference between a LT4 and LT1 throttle body on a 96 car is the plastic top cover that has the "Grand Sport" inscription.
The 96 throttle body is a one year only due to the difference at the linkage. It is identical to the 94/95 throttle body except where my pen is pointing. The 96 throttle body is on the top in the picture. The 94/95 style is shown below it.
Thanks for the great info. I live in southern CA and do not encounter driving conditions under 40 degrees, even in the winter. Next lame question: what does IAT and IAC stand for?
The IAC is the intake air control solenoid. It is a solenoid that controls how much incoming air bypasses the throttle butterflies (once closed). This sets your idle speed.
IAT would refer to the intake air temperature sensor. I corrected my spelling mistake where I incorrectly referred to the IAC as the IAT.
10-22-2018, 11:19 AM
