Expert: Sean Halliday - 8/3/2010

Question
I have a 2005 Ford Explorer with 77000 miles on it.  The vehicle idles eratically when I am at a stop sign or stop light.  This problem just started and I noticed now that the A/C is not properly working.  I believe that the problems are connected and I do not know much about fixing vehicles, so I wanted to get someone's opinion before I take it to a shop.   Thanks.

Answer
The a/c and the idle are related as the engine should idle up with a/c on.If not,the iac or idle air control solenoid,will be sticking or may need cleaned as they build up a carbon deposit.Pull the iac off and try cleaning it with carb cleaner if no good replace the iac.Other causes could be,egr,or vacuum leak.Check all vacuum lines are not cracked or broken.Check pcv valve is not sticking.