IDLE control on EECiV Ford throttle body

Using external 4 wire gm stepper on 89 EFI escort , throttle body has air bypass and throttle plate set slightly open giving vac leak symptom.

Ive had to silicone up the air jet in throttle body and close plate as set slightly open from factory without screw adjustment.

Is this correct that only the stepper will be the only air to bypass into plenum?

If i didnt have pid off will that be why sometimes the idle doesnt change when moving idle ref table setup?