I noticed that when my cooling fans come on at idle, my motor would start running rough. i figured out that it was air from the fan blowing onto the intake filter that was the issue. why I don't understand.
i moved the intake tube out of the line of the fan blast and all is fine, but id like to understand what is going on. I know others have their filters in the fan blast and don't have this issue.
I found I did have some vacuum hoses run incorrectly at first but have them all sorted out now, and the issue is still there.
i made a video showing how a small fan on the intake causes a rough idle. perhaps that is normal?
https://youtu.be/9Ig1KhCTtLI