when I was installing plenum yesterday and took off throttle body I noticed that its door was not completely closed - it had like 1/2 mm gap, if gently pushed it would close completely but then would return into this barely open position. Is it really how it is supposed to be?

For some reason I supposed that throttle door should be completely closed if no voltage applied to throttle body, was I wrong?

It needs to be a bit open for enough air to idle?

Didn't your Mom tell you to not go pushing on things that shouldn't be pushed.

Idle air is the answer

I`m a one of a curious type.

I was cleaning it, actually, it had a bit of residue on its mirror surface so I got it shiny clean again with a it of wd40 and paper towel. That`s when I noticed that gap. Well, good to know, anyway.

I wonder when people were saying here about installing 'bigger' throttle body - intake size of plenum is comstant, naturally, size of incoming pipe from airbox is also set and cannot be increased - what is actually bigger then? Internal size of opening in throttle body seemed to me to be almost exactly same as plenum intake diameter. Is that internal 'bigger' throttle body diameter actually bigger than stock? If yes - who sells it?