my car is a 93 Supra NA Auto..
the problem is when i start the car cold, it idles at around 1800rpm, while its idling the rpm needle quickly jerks from 1800 to 500 and back.. and while its doing this, the Overdrive lights turn on and off.. last time i started my car the smoke was white like a cloud, and the engine shut off by itself. its like misfire..
sometimes when the car is hot already while im driving, the rpm needle also jerks even when im accelerating, from 3000 to less than 1000 and back.. and sometimes the engine just shuts off.. what could be wrong with my car?