Fiesta running very very rich?

hey, i have a fiesta 1.1 1993. i have had a service done to it about 6 months ago and got told my emissions was at 600 grams < i think thats the word for it. the maximum is 300 so its double the maximum. when i get out of the car after driving i smell alot of fuel. and if i rev my car a load of black liquid comes out of the exhaust. and my exhaust is very black at the tip of it. but there is loads of it and all of a sudden my battery light has came on. some times it stays on when my car is cut of and keys out. but my car goes flat over night. so the light might just be that my altinator has gone. the car did cut out on me when i came to the end of a road when my clutch is in. revs drop to 1000 rmp then goes up and down up then goes to 0 rpm. i pulled the acceleration tight so problems ok but must be a problem some where. but i dont no what it could be. thank you for reading. Jay