I have a 88 Jspec t2 engine...

Ok my question. what the hell is this thing? i notice its supposed to have a fat vaccum line going to it, and there is a sensor clip...but mines broken off...How is this affecting my car?

 

Bypass air control valve. That "fat" hose connection is a coolant line.

The BAC supplies air to the dynamic chamber.

 

you sure its a coolant line...looks like vaccum, and when i put my finger up to it i can feel it sucking on it...

 

Well let me elaborate.

There is a vacuum line and a coolant passage on the valve. The vacuum line goes to the air bypass selenoid valve which inturn connects to the TMIC. And there is also a coolant passage on the BAC.