The filter that came originally worn out so i replaced it with a new one...not the kabuli one.
But if it was the fuel injectors than that wud not have been the case on CNG...my car used to start in half sulf on cng in winters but when the problem started...the sulf takes longer both on cng and petrol...plus it vibrates and misses like theres water in the plugs but then gets smooth like anything. and when the car is not cold, theres no such problem..starts smoothly.
so ill check the tappets as per the other suggestions, and see what happens:-#