94 civic with stock d16z6 about 250k on it...she smokes a lil at start up n idle amd even as ur driving... I did valve adjustment yesterday and the motor is quieter and runs fine just curious on what the smokes from... I kno either rigs or valve seals just want some riemforecment... So i Drove the car home today about 15 min drive, let it sit for about 10... Did a compression test and all 4 cylnders were 150-160... Cylinder 4 spark plug is black on the threads and so was the connector after testing cylindr 4...

 

Given the mileage on that motor, it's a good chance it's both.

Was it a wet black, or a dry black when you removed it?