Hello everyone, I am new to Honest John and I could really do with some honest, accurate advice in regards to my C3's problem.

The low down:

(No warning lights, no starting issues, engine jumps to life no problem, battery is fully operational - Volt meter tested)

Okay so here's the story, had the vehicle for 12 months, no issues,
Clutch has been changed at 60K miles. Car has now done 98K.

Recently the vehicle has been unable to keep a steady idle or tick over.
- when the vehicle is started it jumps to life and then stutters, and struggles to keep going if i push the accelerator, or drop the clutch it makes no difference it still stutters and shakes the vehicle. (The engine blockshakes quite irratically.)
After 10 to 20 seconds the idle picks up again, and stays around or over 1k rpm and it is fine to drive.
If i drive the vehicle before i have waited 10 to 20 seconds it strugles and barely moves.
- also if i drive it for a while and come to a junction or stop for any reason you can feel the car running "up and down" so to speak.. the idle rev is not consistant.

Could this be a faulty idle sensor?
Any input would be highly apreciated :)
Here is the car - http://img404.imageshack.us/img404/9823/img00477201004091431.jpg
Thanks, Jake.