1994 Chevy Camaro why car is running sluggish/engine light

My Camaro recently started running sluggish at any given time. The engine light will come on, seeming as though, it is going to die when these occur. It will line itself out and run smooth within a mile of running. Also, it sometimes on start-up it is very sluggish as though, it has been flooded, and has a smell of what seems to be something other than gasoline. I am unsure if this is relevant to it, but I had my Nephew check the spark plugs and they were greased with what appeared to be a vaseline type substance on each plug (is'nt that unusall?). Please HELP with any suggestions.