Hi Girish- what year is the car? Has the check engine light come on during these episodes? Try to get to a local auto part store and have them use an OBD-II reader on your car. If this is a singular or even a recurring problem, your car\'s system should store the fault codes. Once you "pull" the fault codes, the counter-man should be able to direct you to the probable source of the problem; but you should invest in a repair manual for your car that will guide you through the troubleshooting process related to the displayed error code(s). The diagnostic reader does not provide you with the definitive part on the car that is faulty- usually there are a series of troubleshooting steps you have to perform (almost like a process of elimination) to detect the actual source of the problem. Unless you are a seasoned mechanic with access to all the service bulletins specific to your car or have repair experience with cars with similar problems where you are able to recall what the problem is... without the proper diagnostic tools and the proper diagnostic flow charts to assist you in diagnosing your cars problems, repairs can be a long-shot and very costly. Best regards.

Have to check your timing,idle control valve, throttle position sensor

Check over heated.