a light smoke coming out of valve cover, inside of motor and intake filthy, shot blasted intake cleaned valves & reseated them new seals still has a rough ilde any ideas how do u check injectors? exhaust is clean no smoke

 

I know we checked the fuel injectors with a length of hose back in the day... making sure you could hear them operating... of course this is done without taking them out... had a buddy who too them out to clean them in his 300Z... he didn't replace an O ring... had issues with idle until he finally blew it up... darn street racers.

 

Smoke coming out of the valve cover is blow by, the piston rings are worn.