I need some help my 93 GT is acting up today i swaped the (IAB) valve so i notice the car surges at about 1200 or 1300 RPM after that the car runs pretty strong, i also notice a sligth engine noise like exhust leak or pinging. Well i unpluged the valve but the car didn't do nothing, my question is how does the (IAB) valve works i dont know what's going on is it a bad one .I also was messing with the timing and fuel pressure.