TB coolant by-pass and vac. plugs

I was by-passing the coolant lines that goto the TB. And I was told to go ahead and plug the vac. line that comes off the TB. The idle went sorta wild. I relined the vac. this took care of the idle. My question is has anyone done this without the idle throttleing up and down. I was lead to belive that all I had to do was plug not adjust my idle. Also I live in florida where right now its 80 deg. at night and the by-pass for the coolant lines is not haveing a neg. effect on the idle. Its ot like i got a whole lot out of by-passing but its a little push. At any rate thanx in advance for any hits and helps.