Trying to Decide Value of my 1969 Z/28

[SuperNovaSS]

My diagnosis is you need a new mechanic. If the engine has an erratic vacuum signal you could have a vacuum leak somewhere. An intake valve being to tight will also cause this symptom since it will produce a vacuum leak to the intake which will cause 4 cylinder to be effected on a dual plane intake and all 8 on a single plane. Silly question, has the PCV valve been replaced? It sounds like you need to start with the basics like a compression or leakdown test. Also, finding the source of the oil getting into the intake may point you in the right direction.


I hope you can get it sorted out.

Jason