My Mother left her car (1996 Cavalier 2.2) running all night (about 14 hours actually) and now it starts fine (no smoke) but after you drive it a little ways it misfires and pours blue smoke thoughts?
Possible fouled injectors, burnt spark plugs, fuel fouled engine oil, restricted PCV flow. Do you know if it was running even a little hot? If so you could be looking at the headgaskets failing soon. The best thing to do is have it looked at by a professional, and tell them what happened so they can focus on the effects of that first.
May have been an underling issue, this has caused to show itself. I do know of worse, a car was left in a closed garage running until it died on its own, ran hot, radiator busted, sure it blew head gaskets but by time it was discovered it had stopped running and a man the owner and his pet was found passed away from carbon monoxide poisoning in the garage, so this is dangerous. Not the best thing to write on but someone reading this may realize not to forget its running.
Looking for a Used Cavalier in your area?
CarGurus has 20 nationwide Cavalier listings and the tools to find you a great deal.
Search Chevrolet Cavalier Questions
Chevrolet Cavalier Experts