rebuilt my engine and stuck it back in my del sol and the idle is horrible it was fine til i rebuilt it and stuck it back in...it idles up and down soon as you start the car up from 900 rpm to about 3000 rpm it does it no matter how long you run the car everyonce in a blue moon it will idle at like 1000 to 2000 but its up and down i need to to fix this its driving me crazy i done cleans the iacv plz help