88 vette with tpi, when setting min. idle the procedure calls for jumper in adl key on for 30 secs then unplug iac valve.I can hear the iac running when I do this but,It just sounds like a electric motor running.I thought that the iac was pushing the pintle into the seat during this procedure?My feeble memory seems to remember doing this on a tbi a long time ago and it sounding different?What should it sound like?