I wouldnt argue that Rat doesnt have a good case, looking back at the recent posts, I would have to say there are good suggestions, thus far. I just disagreed with him saying a bad valve would "NOT AFFECT IDLE", ( not arguing ) .
, my past expierences with my own EGRless engine is what I based my post on. I had a Exhaust Valve that was half burnt away & my idle was perfect! Then again, I regularly clean my TB, IAC & MAF too.
, you mention that you had the intake off. Are you sure you re-sealed it properly again? Not to doubt your work, but I've seen this happen even with the best mechanics. Some Non-GM Techs forget to silicone the lower intake gaskets properly to the heads at the corners. 1) It will cause an oil leak due to the gasket moved while installing the intake again. 2) If you didn't torque down the intake bolts properly, a uneven gap may result too & thus cause a small vacuum leak among other problems. You also mention you cleaned the TB. Is it possible that a small piece of debris got lodged in there while cleaning & is causing this? Did you clean the IAC too? If so, did you re-adjust it back to it'* factory setting as it is adjustable? What did you use to clean the TB with anyways? If you used Carb Cleaner, it may have ruined a seal or two due to it'* corrosive nature on o-rings. FI Intake Cleaner is ALL that is recommended on these engines. Have you checked the TPS mounting bolts yet? If loose they can effect idle if the TPS is allowed to move from it'* original setting too.[/quote]