If your talking a 20V coupe. I thought those were EFI and has an ISV but there is automatic cold start enrichement from the ECU. If its a 10V CIS, then the CSV is gonna be over by the Fuel distributer next to the intake manifold. There'll be a stainles steel braided fuel line going to it. Easy to spot cause its the only thing other than the 5 fuel injectors which is getting a fuel line and it connects to the intake manifold.

this is on the left side of motor, between the manifold and the airbox..kinda what fusilier said..follow the 6th fueline down to it..cant miss it..its the only blue thing down there.
<img src="http://pictureposter.audiworld.com/78580/luke_083.jpg">

It regulates airflow into your motor and bypasses the Throttle body at idle. The MAF reads a higher air flow and correspondingly adds fuel. Reduce the ISV bypass and the idle should go down. Also chk your throttle body and see if there is an adjusting screw.

reduce the ISV bypass?

It shouldn't change.
Look for a vacuum leak post throttlebody.
Air getting in and a lean run will raise the idle.

Bernie Benz authored it.

Either way, the ISV on the 7A is located on the airbox (bolted to it). My early car was at least bolted to the airbox....