IACV was a concern of mine, especially with the stumbling on really cold days for a minute. The fuel trim readings I am getting off of the scanner lead me to believe that is not the case though, including the bad gas mileage.
Oh I forgot to mention I replaced my fuel injectors too, and compression was very good.
In my integra gs-r there was a specific procedure to make sure the cam timing especially the intake one didnt move when tension was reapplied, but there was no way to lock the cams in. These symptoms (other than happening suddenly) still sound like a timing thing from what I have been reading especially for my case.