Fuel Problem

My 1991 Acura Integra automatic car is not pumping enough gas and it starts slowing down when I am driving, also it sounds as if it is forcing itself since it does not change to a higher gear vovoom sound after the voom sound like it is forcing itself. Well it is wasting way to much gas almost 1/4 of the gas every two days and I am only driving it like 15 miles in two days. Could it be the Throttle Body Injector AKA by dealer as (Diaphram). It looks like it gets stuck when I push the throotle from the hood the little metal thing goes up but it hardly comes back all the way down. The part I am talking about has a circular top about the width of 1 1/2 inch and a little 2" long metal stick that moves as the car accelerates and deccelerates. What other names does this part go by? Please help…