1984 Vic Idle question

I'm new to these forums and I searched before I started this new thread...

I have a 1984 LTD Crown Victoria with a 302 and I have been trying to figure out where to adjust the idle or "high" idle. When I start my car, the engine sounds as if it is about to take off (like a jet engine!). I don't know about anyone else's Vic, but mine automatically kicks itself off that faster idle after 30 seconds or so. I know where the little screw head is just to the left side under the air cleaner, but this does not seem to help with the starting idle when it is cold. First off, I have no idea what the specs are and how to tell... I can remember what it used to "sound" like, but that's about it.

I am not for sure if there are seperate adjustments, or if it is something going on with my choke or what. My main concern is that I am going to cause harm to my engine over time if I do not correct this now; I just wanna avoid taking it to someone and paying them if I can do it.

Any help anyone can throw my way would be awesome. Thanks in advance.

according to the owners manual...you cannot "adjust" the idle

What is the car EFI, CFI, or Carb?

check all of your vac hoses going to and from the throttle body.