there are 2 holes on the inside of your TB after you take the intake pipe off, you cover the 2 holes with your fingers, if it dies, no leak, if it still runs, you have a leak, THEN you use the starter fluid and when you spray it and it wants to die, then you've found your leak, but no sense spraying that shit if it doesn't leak

and mine exhibited the same issues and it was a failed map sensor, unplug it and see if it throws a CEL and if your car runs better

also, are you tuned?

EDIT: don't touch the idle screw if you don't have to, mine was a MAP sensor issue and i had the idle screw out and it still wouldn't idle when it got warm, new MAP and voila, runs like a raped ape