REALLY bad Idle problem Need Help

got a 90 240sx with the SOHC KA was driving fine this morning, but I took her on the high way and got on it abit and now the idle stays at 3 grand. and tonight I was on some backroads and now its damn near at 4. I have no damn clue what the prob is, the engine is still strong and pulls all the way to redline so I figured it wasnt the spark. Any ideas I would really appreciate it? Oh and I thought it was maybe the battery cause that was the prob in the integra but I changed the battery out and still the same prob. I even unhooked my cd player thinking it was the voltage but it doesnt jump up and down it just stays at 3 or above at idle.

Check your throttle position sensor.

My throttle Position sensor....where is this located?

Have a friend step on the gas peddle while you look at the engine. The thing that move will be on the throttle body. On the other side of the throttle body from the throttle cable wheel will be the sensor. If your car is a manual tranny, there will be three wires coming outa there. I would tell you to check the voltage but it seems like you may need some help in the "Mechanic" department. The middle wire is the one to check with a voltmeter. Closed is about .6v and open is about 4v. I would say also check to make sure your throttle body is actually closing all the way, it may be sticking. Just pull the intake tube off the front of it and look. The vein should be completely closed. Also find the Idle control valve, it is a cylindar looking thingy on the intake manifold, about 3 or 4 inches or so long. Unplug it while the engine is running. If you cant locate it I will look at the SOHC KA we have at the shop and I will give you the exact location. If it idles good then the valve is bad. I can get you one for free.

thanks dude i will look at that today I appreciate the help