Idileing and reving problem

[IKneX]

Hey everyone! I got a couple of questions, im new to the toyota supras so im not 100% on this motor ( 7M GTE ).

First question, how do I adjust the idile? it revs at about 2-2500 in park. I was told everything is electronic and cannot be adjusted?

Second, when its in park it will rev up to about 2500, then cut out like if I shut it off, then catch itself around 1000 rpm and keep doing it over and over. Rev up, quit, Rev up, quit ...... and sometimes it will actully go as far as cutting out.

Any help would be greatly appreceated, Thanks in advance!