4.3 engine has miss at at higher rpms ,cruising speed. Has had roto cap ,roto button,wires,plugs, coil pack, fuel spider, mass air flow. Meter , mass sensor and fuel filter have been replaced. With full tune up it did seem to disappear for a week or two. Then came back. Check engine light is back on . Radom miss fire. Please help out of ideas and tire of never fully getting g rid of this of this problem.

 

maybe cps?

 

Did you check the fuel pressure?