cannot adjust throttle body according to procedure. the speed will not adjust up or down with paper clip in a and b and ignition on and iac unplugged.

What is your question?

have new iac and rebuilt throttle body from rock auto. Idleing at 1800rpm with or without iac in place.

What makes this problem better or worse?

N/a

How long has your 1994 GMC Yukon had this problem?

long time