Need some tips!

Cold start- idles fine at 1200 rpm
Idle warm - 750 rpm
Start up the car when its hot- idle is rough, misses all the time. It doesent help if I rev the engine. But if I drive away and then stop the car it idles fine. Shut of the engine and start it up again and the idle is rough again.

Any ideas?

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GTA -89:383, 4-bolt,Free flow muffler,dual 3" HF cats, Edelbrock headers, Canfield heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTR, !plenum, 52 TB, MSD 6AL, TPIS level V prom, Superior shift-kit and all the minor mods,looking for a SR ...
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)

 

i have same the problem im begining to think its because of my ported maf because i have read in car magazines it can affect drivability also try checking your maf burnoff relay to see if it clicks during engine shutdown.