I have a 95 grand cherokee with the 5.2L. When you are going down the road from about 55 MPH TO 70mph it surges? My gas mileage is horrible when this happens, if I don't give it more gas or lift off my mileage drops off. It idles just fine, runs fine except when its doing this "surging"

dont be so lazy when you write. I cant guess what is wrong if you dont state complete thoughts. when does it surge? check for vucuum leaks. look for hoses comming from the intake manifold that are off broken and rotted.

DOUGH! sorry, my mistake i just re read it, it sounds like the Throttle position sensor has a flat spot: http://www.partsamerica.com/SelectParts.asp?SourceArea=&PartType=280&PTSet=A&Description=Sensors&SourcePage=PartTypes&SearchFor=Throttle+Position+Sensor