Same happened to me abt 1.5 yrs ago.
The problem was carburetor, but when I asked for carb service, mechanic at toyota walton suggested that "sir carburetor ki service na kraaein, aik dafa khul jaye tau waisa nahi rehta, aap carb cleaner spray krein", so I did same..and all was set, purchased carb cleaner,
After that, problem occurred 1 2 times again, sprayed same cleaner. And after that no problem occurred.
(Carb service was 1600 frm toyota walton, cleaner just 250).
Make sure u spray carb cleaner when engine is full hot. Its also mentioned on cleaner bottle.
Also take advice frm other mechanic.