checkfor a vacuum leak, and scan for codes and check fule pressure you can't adjust the idle, clean throttle plate and iac hole as wellwith choke cleaner.

does the idol change at all from start to warmup? the IAC valve is the computer idle controller. you can check it by removing it and looking inside there are 2 holes and a rubber stopper on a rod going between them on the inside. check that stopper is seated/seats and there's not lots of crud in there. you can test operation by applying 12v to it while off of vehicle and watch stopper open and close. other possible reason for high idle is broken/cracked/loose VACUUM line somewhere. usually attached to the intake runner back top of engine and along firewall there are many connections to check.