The only way to adjust it is to move it around a little bit. I'm not joking. I don't know what the voltage is supposed to be. Snug the screws into it and have a buddy sit in your car and tell you when the idle is where you want it while you move the TPS around a little, then tighten it down.
EDIT : Mity, save up for a plenum. Don't do, basically, the same job twice. AND the TB and plenum kinda work together. You won't notice much just from the TB.
EDIT AGAIN : I see your sig says C&L elbow. Is this the plenum? If so, disregard the first EDIT.