Where exactly is the BAC valve on an S4 FC? I've read some places saying that the BAC valve could cause a problem with idle also. Anyone else experienced this problem? Even better question...Has anyone fixed an idle problem?

 

The BAC for your TII is located on the passenger side of the upper intake Manifold. It has 2 coolant lines attached to it, one air line, and a connector.

 

And we've fixed 'em before also. Used this article to fix 'em if broken. http://www.teamfc3s.org/info/articles/idle.html