another IAC question

94 LX Tbird. For the past month and a half, I've noticed that my idling after startup has been screwy. The rpm's will drop below 500 when i'm backing out of my driveway and when I come to a complete stop at a stop sign or traffic light. This droppage will only last a second or two and then it's back to the normal rpm range. After like 10 mins of driving the car is fine at traffic stops.

After two weeks of this, I bought a can of CRC Air-Intake Cleaner and sprayed the IAC out. The rough idle practically went away. However, a week later the idle troubles returned. This past weekend I put a new IAC valve on and I'm still having the same problems. The IAC valve was purchased at a Ford dealer. Is there a time period that I must wait for my car's computer to adjust to the new part? Second, if the IAC isn't the problem, then what should I look at next?

Did you disconnect the batterey for a while?

Have You Checked your MAFS Or Clean Your Throttle Body...Oh And Make Sure You Check All Of Your Vacuum Lines...They Control Some Pretty Stupid Stuff....

I did not disconnect the battery after the switch.

About two months ago, I removed my MAF (very carefully) and the bulb appeared to be clean. So I didn't do anything to it, plus I have read that the MAF is easy to break. I have not cleaned the throttle body either.