Lumpy 206+

[PugLover]

Hi all,

I have a friend and he has such problem in his car. He brought his car to many garages but no solution yet. I hope you can help.

He has 2011 model 206+ 1.4 comfort with petrol. When the engine is cold, after the engine fires up, after 5-10 secs. the car becomes lumpy. When the car starts moving, it revs up gradually and accelerates suddenly. This problem is more visible if he presses the clutch pedal all the way down. If the clutch pedal is released, the car is again lumpy but not too much.

When the car is once warmed up, no problem at all. Everything is just fine.
Throttle valve is already cleaned up. There is no error code in diagnostic.
What could be the problem?

[PugLover]

Any clue would be appreciated