Check out the thread at the top of this page :eyepoppin
Your car is doing what it is supposed to do. Your A/C compressor takes as much as 15 hp to turn when the clutch is engaged so the computer ups the rpms and adds timing to help the engine compensate for the extra load. Your idle is dropping every 10 seconds because your A/C clutch is disengaging.Stang454 said:On my 2001 GT it idles fine with no AC or Heat on at 755 rpm's. But when these are on, the idle will jump up 200 to 300 rpm's and then go back down every 10 seconds or so. It's almost like the power isn't there. The car has 45000 miles and has xpipes,cat back,Predator tuner K&N Filter. Any ideas?:eyepoppin