obsessed

I have owned this Cherokee for 4 months. It has recently started acting up. The Jeep idles and runs very well, but sometimes it will start to miss when I take off from 0 to 30mph. After I get to 30mph, it works itself out and the Jeep runs fine. It might not run rough again for 2 weeks. At the same time, my temperature gauge has read overheated at 260 three seperate times. When I pop the hood, no fluid is boiling over from the reservoir. I get back in the Jeep 3 minutes later, start it up, and the temp reads normal at around 190. I have changed the fuel filter and put a can of c-foam in the tank as well as put in new wires, plugs, and distributor. Could bad temp sensor cause these problems? Does this sound like a fuel problem or electrical problem? Any help is grealy appreciated.