I know that this has been discussed before, but I am still a little confused about which way the flow goes. My valve did not come mark as illustrated in the manuel, so I took a guess that the flow goes from throttle body towards the manifolds- not the other way around. Am I right or wrong?

Thank you for your inputs.

 

You're right. It should open when air flows from the TB to the engine. Close when air comes from the engine. I had a similar issue, only I just didn't have the IAC check valve and picked up a PCV valve from Pep Boys. Works fine.

Zach