Fix high idle on a 1992 ford thundrebird

Did you check the fuel pressure? Possible restriction in exhaust system.

If it idles high, with it in park, block off mouth of throttle body with something, it should kill the engine. If very little or no effect on idle, you have false air getting in there from somewhere.
Make sure throttle valve is closing, where applicable, take throttle cable loose, see if idle returns to normal. Check and clean idle air system. Any applicable trouble codes?

on the throttle body. the gas pedal cable from inside the car leads under the hood on drivers side to the throttle body. throttle body is attached to the intake.
*****you should not have to adjust your idle. itusually means that there is a bad sensor if your idle has changed suddenly,****
what exactly is the car doing? ex.fluctuating rpms?, low constant idle?, high idle?

disconnect the throttle cable from the throttle body. follow the throttle cable around the engine and you will find it goes through the fire wall and connects to the gas pedal. disconnect the cable from the gas pedal and pull out of the cab compartment from engine side. Pay close attention to how you disconnected the cable from the gas pedal and from the throttle body because you will have to reverse this procedure when you install the replacement. You will need an assistant who is pretty flexable to connect the cable to the gas pedal. so let the assistant disconnect the old cable from the gas pedal so he or she will know how to connect the new one back to the gas pedal. It was not an easy project for me and it definitely is not as easy as it seems to be. You will need plenty of time, daylight and patience. The replacement cable may be shorter than the original and that ok. Ford has made sure it will work. Use tie-wraps or zip-ties to hold the new throttle cable back in place around the engin. Good luck.

The spring or wire that connects your pedal to the throttle body may broken or damaged. Check under your hood and look at the throttle body (it's the carburetor looking thing). There should be a steel wire connected to it coming from the back of the engine bay. It should connect on the side where you'll see a few springs. If nothing looks broken there, turn the part of the throttle body connected to the spring and wire. If it revs up when you move it, then the cable could be broken somewhere between there and the gas pedal.

Alternatively, the linkage on the pedal could have been disconnected some how. Check behind and above the gas pedal to see if eveything is connected properly.

lube-oil the peddle and cable-do both ends of the cable-check the return spring -it may be weak-you may want to replace it-cheers Denny

Could be a vac leak, or a faulty idle air control valve on the throttle body.
The computer controls idle speed by regulating the amount of air entering the intake.

First check to make sure the throtle cale is moving freely. do this by taking the throttle and making sure it is fully closing. it is very possible the cable is sticking within the cable housing. next you should clean the throttle body and make sure it closes with no cable attached. then check for any codes related to the idle air control motor.

For this types of problem,there are few help inks to troubleshoot the problem.Click the link below to go through the troubleshooting procedure to resolve the issues :----Idles rough and quits when gas pedal is pressed less? http://technoanswers.blogspot.in/2012/01/1999-ford-f-150-idles-rough-and-quits.html-----------van idles rough? http://howtobyme.blogspot.in/2012/01/2004-ford-freestar-van-idles-rough.html
--------------runs lean and idles rough? http://technoanswers.blogspot.in/2012/02/ford-runs-lean-and-idles-rough.html
-----------Car still runs Rough after tune up? http://howtobyme.blogspot.com/2011/12/car-still-runs-rough-after-tune-up.html
------------Idle flair is noticed on car? Rough idle? car will not idle? Erratic idle speed? http://technoanswers.blogspot.in/2012/02/idle-flair-is-noticed-on-car-rough-idle.html
----------High rpm in neutral? Inconsistant high RPM in neutral? http://technoanswers.blogspot.in/2012/02/high-rpm-in-neutral-inconsistant-high.html
------------Engine Backfires? http://technoanswers.blogspot.in/2012/02/jeep-backfires.html----------- Nissan stalls and bucks on Acceleration?

http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html

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Nissan Pathfinder Backfires? http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-backfires.html
---------How to adjust rpm? http://schematicsdiagram.blogspot.com/2011/12/how-to-adjust-rpm-on-2009-dodge-charger.html
------------Engine cuts out at 3000 RPM? http://schematicsdiagram.blogspot.com/2011/12/engine-cuts-out-at-3000-rpm.html
----------This will help.Thanks.

Crank Position Sensor ? I guess you don't know what that is !

You already answered your own question,when you pulled
on the gas pedal