Problem with my old mans car

[I get around]

Essentially when you turn it on it revs slightly on its own without any input from the accelerator.
The exhaust fumes smell like petrol very strongly too.

However it drives fine.
it's a 1.8 citroen xsara by the way

Any ideas what it would point to?

 

[I get around]

Sorry I'm having trouble explaining myself today, bit hung over, bored nonetheless, it's running rich all the time (fumes stink of petrol a lot) and it's revving more than it should on startup if you know what i mean.

 

[I get around]

No it's still more than idle when it's warmed up.