Unburnt fuel smell

I have a problem with my fuel injected car in that if it is idling for a while it starts smelling very strongly of petrol almost as if it is leaking.
Does anyone have any idea what could be causing this?
Thanks

Engine type, make and model as well as year goes a long way to get us the information to assist you.

I think that it is a k jet engine and the car is a 1993 convertible.

Do you have any sense of where the small is coming from, eg engine bay?

I'd obviously be checking all fuel lines very closely with the engine running, for signs of leakage through fuel lines or perished rubber hoses, as well as the filler neck, for signs of possible vapour leaks

Take a photo of the engine high res.  Valve cover and to the left and right of the bay.

The reason for the info is that we need to see which fuel system you have,

Raw fuel smell could be but no limited to:
Fuel hose leaking
Vacuum hose leaking
injector seals leaking
cold engines and cracked exhaust manifold leaking.
Intake manifold leaks.

Certain systems (Digifant) or (CIS) as well as Carbed all have common things that leak more than others. Knowing what you have exactly will help up help you quicker and with less monies and time wasted.

Over on this side of the pond all 93's had Digifant II  
Ya'll had more options avail over there than we had over here as far as engine types as well as fuel types..

I just find it strange that it only smells when the car has been idling for a while, normally it is fine.