90 path high idle and wont start after drove
 

I have a 90 pathfinder w/V6A week ago itstarted idling high about 1200 rpms use to be 800 rpms when I drive it and turn it off and go to start it it just cranks. If I wait about 20mins to an hour it will start and drives fine. except high idle.checked for vacum leaks,cleaned throttle body, new timing chain, plugsabout 3000 miles ago, new fuel filter and air filtermonth ago. Need Help!