I'm kinda stumped about this one. I have the dreaded idle issue that's going up and down and up and down....it's on a 93 honda accord first of all, I did the usual bleeding to the car, checked for any vacuum leaks- didn't find any, replaced the iacv. I know the usual cause is the fitv, but it works as it should. I took it off and tested it, cools off it opens- it heats up it closes. What I'm confused about is the channels in the throttle body. I know the upper is the iacv and the lower is the fitv. Question 1- I assumed the fitv was bad so I blocked it off temporary till I get a new one, thinking it'll stop the idle issue. When I block it off there shouldn't be any Sucks on right? But there no chance at all!! Is that normal, or is there an issue with the intake manifold? Question 2- the iacv, at idling is it supposed to give suction - or only when it calls for it like when the ac is on. I'm fairly fluent with vehicles, but this is kinda racking my brain

 

I hate spell check!!!!