I had the same issue with my 1988 model. I tried adjusting the transmission linkage, fuel system cleaners, new spark plugs, distributor. And in the end it was the TPS unit.
The TPS (throttle position sensor) is on the side of the throttle body just under where the large hose from the air filter connects, at least on my model.
It was very easy to replace and set to factory specs (looked em up online). Once I replaced that it was like my 170k mile jeep was brand new. Quick to respond to the gas, and all hesitation gone. Whole procedure took less than an hour