All spark plugs look lean. Random dead miss. Sometimes runs fine. Not overheating and oil pressure is fine. Any input would be appreciated

 

[QUOTE=cbrandon;20136]All spark plugs look lean. Random dead miss. Sometimes runs fine. Not overheating and oil pressure is fine. Any input would be appreciated

/QUOAl

Also forgot to mention had a bad valve cover gasket leaking at the rear of cover. Is there another sensor at the rear of the engine that may have been saturated with oil that may be the culprit?

 

Have you seen this thread? The CAS is on the left rear of the head at the valve cover. https://www.miataforumz.com/na-1989-...oorhouse-1631/

The o-ring around the CAS also is a common culprit for leaks. The one inside it is a common source of failure for the unit.