Where is the IAC vavle located?

 

right next to the throttle linkage on the manifold (to the right). It has an electrical connector and two hoses connected to the bottom of it.

 

Look in the center of your block and look directly back. Its located directly in the center on your intake manifold. There are two bolts holding it onto the manifold. One is longer than the other, so remember which goes where. Be careful not to make a mess and have a rag handy when disconecting those two hoses because they have antifreeze in them.