that black gasket around the vtec solenoid is the gasket u need to change out.

Also get a magnet and pull the piston out, there's a spring underneath it, (BE VERY CARE FULL W/ IT CAUSE U CAN LOOSE IT EASILY)

check the spring to see if it looks/acts normal and yeah, spary some carb cleaner in there and if u can stick a tooth pick to clean sludge thats probably stickin inside too (also w/ the solenoid)

The screen/filter, goes b/w the head and the piece that the vtec pressure switch goes in. i dont see the pressure switch in teh pics, will have to check another f23 accord to find it. if u know what i'm talkin about, just pull taht out and clean it w/ a carb cleaner.