I need help! My supra idles rough at cold starts...=(

[idoke]

1991 Toyota supra turbo
5 speed

One morning, my supra started idling funny. I remember turning it on. The temp gauge shows Cold and as I was driving it. At first, it runs good until it started warming up. As soon as I came to a stop, the engine started idling funny and at times, it will die (Only if I was to put it in neutral) When in gear, it runs but kind of wierd. I shut the car down for about 3-5 minutes. After that, I started it up and took it for a test run. Amazingly, it ran fine again. It does this every morning or every COLD start. ???? What's going on? I really want to fix this problem and I'm calling out to all Supra owners and fans to really help me. Please help me for I am a supra fan in need. Thankyou.