high revs

[jimmyninja]

Renault scenic revs up to 2500 -- 3000 rpm when started from cold then ok after 5 or 10 min

[123everton]

Petrol or diesel?
Sound like a mixture problem.
If it's petrol check the spark plugs and see if it's running too rich.
I'm not a mechanic, so that's all I can offer you until the wiser heads log on tomorrow.

[TWR]

Depending if your accelerator is positioned on your car floof, if on the floor chack that there is no dirt within the area, if so clean and lubricate WD 40, Check under the bonnet ans spray the links with the same.