high idle help

check, idle, throttle, body, screw, die.also, 5spd, needed, advance, problem, mins, settles, 1.5k, start, tune, high, research, iscv, looked, hoses, vacum, revs

when i first start the car it revs at 2k then settles down to 1.5k after 5 mins or so. i have done a tune up and looked at some of the vacum hoses. i been doing some research on here and check the iscv and it did almost seem like it was going to die but didnt die.also the screw is all the way down on the throttle body. is there anything else i could check to be able to fix this problem?? thanks in advance 91 mr2 na 5spd if needed