My idle seems to sit wherever it feels when you let off the gas. Sometimes it will be perfect at about 650-800 which is fine with me, other times it will sit at 500 or so. It won't ever cut off or go high but why does it idle wherever it seems to feel like idling? I've recently replaced the head on my motor, did I mess something up? Its a 2000 motor so I would assume the IAC to be o.k., could a leak on the intake manifold where it meets the head cause it or what????? Any help would be apprecited!! I'm going to replace all the vacuum lines tomorrow for the fun of it to see if that helps. I've already taken my IAC off and the filter looks fine and it looks clean inside.

 

If you only have a varience of 1-200 rpm, adjust it with the idle control screw, or make sure your throttle cable isnt too Taught(ive always wanted to use that word). Id just leave it and run it if I were you.

 

I've adjusted it and it will stay aiight for a while then keep dropping too low. I can't just keep unscrewing the adjustment screw forever.