The other day my '98 Century, which has always run just fine, just suddenly started running very rough: I was in a dept. Store parking lot with the engine idling and the heater running while I waited for my daughter to run in. After about 5-10 minutes the idle characteristic went from smooth as you please, just like always, to suddenly running very rough - almost like it's severely out of time or missing badly - and would only stay running if I constantly feathered the throttle. The key word here is "suddenly:" It just turned on a dime. There were no accompanying events or noises; nothing crunched or squealed, no grinding, etc. I had to have it towed home because, though it "runs" after a fashion, any attempt to put it in gear would immediately result in a stall. Oddly, when I connected my OBD-II reader it returned "NO CODES."
Again, it will start and run for a moment after several turns of the starter, but without constant throttle attention it will die immediately, and even then I can't keep it alive for more than a moment. Ahy help would be appreciated, thanx.
Wednesday, February 20th, 2013 AT 2:46 PM