I have a 92 z34 3.4 5 speed that idels at about 3000 rpm for a while then all of a sudden it will idle up and down. for example it will go up to 3000+ then drop rapidly to 700 rpm and then keep doing it till it decides to stop then it may run fine for little while then do it all over again.it mainly idles 3000+ upon startup.i changed (TPS) and (IAC) dont know what else it could be please if you have any answers im all ears..THANK YOU..
