So basically my jeep is running solid however when I use certain throttle pressure/ cruise at highway speeds 55-65mph it seems to cut out rapidly or shutter/vibrate.. Here's what I've replaced so you can narrow down your suggestions.. Rear shaft ujoints, fuel pump, fuel filter, spark plugs wires cap and rotor. I have 4.0 6 cyl auto trans any help would be awesome this is really aggrivating Thnx