93 trans sport fast idle

This one is driving me nuts. Here are the symptoms....
after cold, warm or hot start, engine idles between 1400 and 2100 rpm. "sometimes" a sharp tap on the accelerator pedal will bring it down to about 1100 rpm. Usually, if I drive the car a short distance and get it up over 35 km/hr, and bring the car to a stop, the idle settles in around 850 rpm and idles very smoothly. On occassion, even after getting up to 35 km/hr it does not settle in, but to resolve this I stop, put the car in park and it settles on down to 850 rpm. I have changed the TPS and the IAC valve. I also cleaned the throttle body with a throttle body cleaning agent. Plugs have been replaced with bosch platnums, wires replaced as well. I have verified all vacuum hoses - all "seems" ok. This is driving me crazy and with winter quickly approaching this high idle condition could get dangerous. Any suggestions would be much appreciated.

With engine off, does the throttle return to idle position? If not, spray some cleaner inside and outside the shaft again. If not, it sounds like a TPS. Had the same problem, surging and uncontrollable.
Get the codes and this may get you to the problem area. Codes are easy to get on this year. No special equipment.

Well...simple things first, I agree with all of the above...and....I'd check to be sure the throttle cable itself has no corrosion or chaffing, and try WD40 wherever it can reach the inside of cable, at both ends. Also check pedal linkage.