2.) Defective TPS - replace TPS. An idle that sticks high and won't come down unless you turn the key off & restart the engine is a sign of a bad TPS or dirty TPS electrical connections. The Idle will often start up at normal RPMs and then slowly increase in RPMs as you drive.
Disconnect and clean the TPS electrical connector using a jeweler's screwdriver to scrape the outside of the male pins and inside of the female pins. Use some WD40 to wash things down after you finish scraping. Check and clean the white 10 pin electrical connector pins (see item #6). Clean pins 1,2, & 5 since they are all TPS related.
Setting the TPS: you'll need a good Digital Voltmeter (DVM) to do the job. Set the TPS voltage at .5- 1.1 range. Because of the variables involved with the tolerances of both computer and DVM, I would shoot for somewhere between .6 and 1.0 volts. Unless you have a Fluke or other high grade DVM, the second digit past the decimal point on cheap DVM’s is probably fantasy.
Since the computer zeros out the TPS voltage every time it powers up, playing with the settings isn't an effective aid to performance or drivability. The main purpose of checking the TPS is to make sure it isn't way out of range and causing problems.
The Orange/White wire is the VREF 5 volts from the computer. You use the Dark Green/Lt green wire (TPS signal) and the Black/White wire (TPS ground) to set the TPS. Use a pair of safety pins to probe the TPS connector from the rear of the connector. You may find it a little difficult to make a good connection, but keep trying. Put the safety pins in the Dark Green/Lt green wire and Black/White wire. Make sure the ignition switch is in the Run position but the engine isn't running.
Thanks to jrichker and others for this snippet from the 'surging idle checklist '