car keeps stalling.. and im stumped!

[GnArKiLl]

my 93 talon has been having a problem ever since i finished the 5spd swap... mods are fic 650's, pte 50trim,3"gm maf,255 fuel pump,afpr,boost set to 15 for now.. the problem is the car wants to die everytime i stop, if i push the clutch in befor the rpm's settle it will die. if i take it out of grear and coast w/o the clutch in it will die every now and again, but nomatter what if i take it out of gear and coast up to my stop the rpm's drop to about 500 and then pick up... i have checked for boost/vac leaks and found nothing. i changed the closed throttle switch. still nothing.... what else am i missing???