Most of the TBI ECMs auto zero the TPS. Which is why they are non-adjustable. Anywhere between .4 and .8 volts works.

I shoot for 5 - 10 IAC steps on a warm engine with no other loads. This has the idle fuel being pulled from the bores and through the blades as it should be. Too many IAC steps and too much air bypasses the blades. This hinders the pulling of the fuel past the blades.

RBob.