Ford Repair: Strange Idle, mass air sensor, mass air meter

Question
I have the exact same problem as this guy in, the link below, with my '01 3.8L V6 manual trans Stang...


http://experts.about.com/q/811/3908170.htm

My car actually pulled itself down the freeway this morning. I didn't have the cruise on and my foot was off the gas. The thing stayed at 75MPH. While sitting at a light or any time I take the car out of gear it will rev.

I went ahead and replaced the TP Sensor and that helped some. Now, instead of revving to 3000RPM it only goes to about 2000 before leveling off. It will then step down a few times with about a 10 second delay inbetween.

I'm going to reset the computer in the morning and see if that helps.

If it doesn't work what would be the next step?

Answer
David-

  Wow...I've got to say that I'm suprised to see a question I answered showing up somewhere online.  I can honestly say that's never happened before...to my knowledge.  I still say that the Ford "answer" that the idle is a failsafe is crap.  If it was a failsafe, it wouldn't eventually return to normal idle.  If resetting the computer doesn't work, I would suggest cleaning out the throttle body and mass air sensor.  This can be accomplished by spraying a small amount of carburator cleaner through the intake (after the air filter, of course, but before the mass air meter) with the engine running.  I MUST emphasize using SMALL amounts at a time.  That stuff is flamable and you'll also notice your engine rpms increase while doing this.  But using too much can cause a backfire which is dangerous if you're anywhere near the intake tract.  A few quick, short bursts over a few minute's time should be enough.  If that still doesn't help, you might check your idle air control solenoid (or IAC).  This helps regulate the amount of incoming air and if it's allowing too much air at idle, you can have problems.  I should also note that with the installation of a new TPS sensor, it's important to make sure it's calibrated properly.  I'd say anything between 0.90-0.95 is within reason and makes for good throttle response.  Anything more and risk tipping over 1 volt.  If you're not too handy with a voltometer, this may be something to leave to a shop (unless you had a shop install it in the first place, in which case I'd hope they adjusted it right).  Hope this helps.  

Steve