high idle from "P" to "D"

What is your question?

when car is warmed up good, then switched off an left for 15mins and i attempt to restart sometimes it starts and dies twice. i just tap the gas pedal a little to keep it from dying. when released it idles ok. but the main problem is when i put the transmission into drive the engine rpm goes up to 1200rpm also reverse is the same. when diagnostic was done no trouble codes came up. help plz.