hunting and low idle after deceleration

[anc]

i have a 76 911S w/ 90k on it, she sometimes hunts, but if i change the mixture settings i can regulate that to some degree, but after the car is warm and decelerates, approx. half the time, the idle goes very low, if i tap the gas pedal, the idle returns to normal (950-1000 rpm), any suggestions? does this 911 have a deceleration valve? should i change all my air hoses? thanx