On a few occasions lately the idle speed on my 1991 745T has jumped well above normal when I put it in Park. Normally it idles somewhere around or just under 1000 rpm, but when it jumps up it goes to around 1500. Only on one of these times do I recall that it seemed like it was idling too high while still in Drive, immediately prior to putting it in Park. It has done this with the A/C both on and off. A quick stab at the gas pedal to kick it down (carry over from the old days of ancient and mystic things called "carburetors") does nothing.

I have always noticed this when I am putting it in Park prior to parking it. Have never noticed any problem at traffic lights, stops, etc.

Any ideas or suggestions of where to begin looking for the cause?

Thanks for any help.
--
Scott Cook - 1991 745T, 1985 RX-7 GSL-SE, 1986 Toyota Tercel (Don't laugh, it is reliable, faithful AND gets 41 mpg!)