car wont idle
 

i have a 91 miata that wont idle

car will start up fine it will sit at a high idle of about 1500 rpm's which i dont mind for now. then after abour second its will slowly drop and stall. if i give the car gas it will stay alive for as long as i want. the throttle is also very sensative. a tap will send the rpm's souring. any ideas?