I have a carburated 83 camaro 305. Whenever I park my car and pul out my key my car keeps running. It doesn't run like it usually does, it just keeps barley turning over. I know that my valve guides are going out because of the oil smoke coming out the exhaust at start-up. Is the samme thing happening with my intake valve. I think that since the valve guides are leaking there is gas getting past the intake valve and that is what is keeping it running. What I don't understand is how it keeps turning over when the spark plug isn't igniting. I am planning on buying a new set of replacement heads i just wanted to make sure that it was the heads so that i know there is no other thing i need to fix or if a new set of heads woud fix the exhaust smoke and dieseling. I would really appreciate any help or any info because it has gotten pretty bad. My car ran for almost a minute after i pulled out the key .