My mechanic and myself have completely stripped down the carb ,checked and cleaned. Also checked the accelerator pump. Put the carb back in place and the problem still persists. I tried the car on a 10 mile trip and had to increase idling speed to 1500rpm to avoid stalling in traffic although cruising on gear is normal. But idling even at 1200 rpm is not smooth. I will replace the air filter next but I do not believe this could be the cause. Sometimes the engine just dies when idling but there is no problem to start again.