I have an 84 CJ7 with a 304 upgrade. My jeep will randomly start runnig very rough, like all cylinders aren't hitting. I will barely idle and often won't. I have to keep my foot on the accelerator to keep the idle up enough to get home. The odd thing is, I may start it tomorrow and it be fine. I may drive it a couple of hundred miles before it does it again or I might only get a few miles. It is very random. I have replace the ignition module, plugs, plug wires, coil, distributor and rotor cap. I replaced fuel filter. Any suggestions?