I moved your thread out of the "parts for sell section." for future posts please make sure your in the correct section, otherwise no one might answer as promptly.
check to see if your MAf is plugged in securely. then run a diagnostic. also what type of engine do you have in it? also check out your cold start injector. Please state when this started happening, did you do anything before this to your engine that might of affected your symptoms?
I did just a quick search for "idle" on this forum and returned these results
http://www.toyota-supra.info/forums/...-low-idle.html
http://www.toyota-supra.info/forums/...dle-issue.html
http://www.toyota-supra.info/forums/...-start-up.html
and this is just your basic TSRM trouble shoot for crapy idle at start up
http://www.cygnusx1.net/Supra/Librar...Section=IG&P=3
http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx
is for checking the codes. please do read through the links i posted. they lead to more troubleshooting guids.