Efi Question

[93ls400walt]

Any one have any malfunctions of their IAC or DP? If so what problems did they cause in your cars preformance? Also where and how do you adjust the idle speed? And where does your car idle at? The manual says 650 +/- 50. My warm idle in park is just short of 600. And in drive it's right at 450. Both without the a/c on.

( IAC= idle air controll valve ) ( DP= dash pot )

Thanks, Walt