need help with this
 

I have a 1987 rx7 t2.It misesout when it idles and it dont want to run but when you push the gas it is fine.And when i was driving it today the boost went all the way up and was cutting out.But now it will go half way up when i get on it.It sometimes back fires when im trying to make it idle.It dont this before but it stoped 2 other times.Need help?It has 87,020 miles on it

tune up!