jeepin-it

Alrighty here we go, I have a 97 Cherokee country with the 4.0. My cel comes and goes day by day. On cold starts (no matter the outside temp) it will misfire and throw a code. The code is cylinder misfire detected in cylinder 2. So far to diagnose the problem, I have replaced plugs, gapped them correctly, replaced wires, cap, rotor, and tested the electrical connection to the injector. I have also tested the compression in cylinder 2 and it is still going strong. The misfire is only at idle and once it warms up (like 5 min) it goes away? Really confused, any advice is appreciated! Thanks