I have a 4.0 liter that I have replaced the IAC on several times. Somewhere I read that the tip of the plunger measured from the mounting base s/b no more than ???. Also how can I tell where the plunger is in tis cycle? I want to try one more time before taking to the dealer. Right now it is idling at 1100 to 1600 and I can't drive it. Someone told me that there may be a way to get the engine to adjust to the new plunger by turning the key on and off several times?