I add my car to your list
miss fire cyl #4 up to 4500 5000 RPM only, idle RPM cut a litle bit at cold , ok when is hot
Have a brand new short block
change injector ,spark plug ans coil pack
the trouble are alredy there.
I clean the MAF,... ok for 15 minutes ...
alredy the cyl 4 possible a bad valve ?