1999 Chrysler Sebring

My girlfriends car has to be warmed up for fifteen minutes before she can drive it anywhere, otherwise it shuts off when coming to a stop. Mor specifically the rpm meter bounces up and down before dropping so low that the lights in the car dim before cutting off, it also is accompanied by the weird whining noise that seems to be coming from the engine. She has had a tuneup, alternator and starter changed, yet the engine light always comes back on and it starts the same process again. Please any advice would be appreciated, its a chrysler sebring lxi v6 two door. Original engine.