ive got a 89 rs turbo, its had loads of problems running lately, it was running fine last sunday afternoon, then decided to start misifring and then cut out, the fuel pump relay had some dodgy wiring and the relay ws burnt out so got it fixed along with a new rely straight from ford, but he problem still exists. The relay works fine the fuel pump primes and the car turns over, nearly starts then doesnt, you can smell fuel and the spark plugs are full of carbon. any suggestions before i starts replecing things???