1.8 Golf MkIII - Revs drop on idle and loss of power, not when cold - MWVWMKIII

Hi,

My car is turning into a nightmare to drive. It's been into a garage twice and had an air leak sorted and had a part replaced (can't remember what it was, but close to the size of a packet of cigerettes and the seal was shot on it).

Still got the same issue. Revs drop right down to aroun 200 then back up to idle. This leads to loss of power when you are lightly applying power to maintain speed.

Its OK when the engine is cold and when you put your foot down to accelerate.

Thinking of getting rid if I can't fix it.

Any ideas welcome.

Mark