Yea, some guys block off those coolant lines. Their purpose is supposedly to cool off incoming air, but the air probably isn't that hot coming through the TB and those lines may actually end up warming the air coming through. That is the thinking that leads people to block them off. In reality, it probably makes little difference and would have a negligible affect on performance. That being said though, mine are blocked off
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Oh, and these lines should have no effect on your stalling problem. Cleaning that IAC valve would be the first place to start. And as mentioned before, the screw under the throttle body will adjust your idle by changing the stopping position of the butterfly valve in the TB.