The car has the following symptoms:

*Rough Idle
*Hard Starting
*Hesitation
*Spark plugs had a thick black carbon deposit along the electrodes, (I noticed this today while changing the plugs)
*Engine Oil smells like gasoline. (noticed this also today while changing the oil of the car)

I'm pretty sure the car is running rich, but i have no idea what might be causing it...
Any ideas of what might be the cause?

I checked the air filter and it looks good, as well as the new set of plugs.

BTW the car is not my Teg, is a 95' Toyota Tercel