Hello I have a 1990 HONDA ACCORD F22A1 203,000 miles when I purchased the car it had this problem but it seems to be getting worse now. With the car in park and driving it happens but when sitting in park listening to the engine roughly 1,500-2,400/2,500 rpms its like engine surging or hiccups then as I get higher around 1,900-2,400/2,500 it seems to hesitate and surge/hiccup a bit worse then you hear this almost like somewhat metallic rubbing almost like something metal rubbing together although it isn't loud at all its coming from under the valve cover that all happens til roughly 2,400-2,500 rpms then the engine runs perfect past that at any level with no popping out the exhaust hesitation/bogging or hiccuping. Also the car idles perfect at 750 rpms smooth idle. Any help would be greatly appreciated thank you in advanced for anyone that helps I would just like my full power back around that rpm level. Also when this happens I can feel it through the steering when like it shakes it a little almost felt as a hiccup or a little hit.

 

do leak down test.