My erst engine in my fiesta,starts then cuts out, i checked the plugs all covered in petrol, i pushed the plunger on the metering unit down and there is also petrol sitting in there, and when u do get it to go it smokes black smoke a bit, sound like its in need of adjusting? the engine is fresh i cant see it being the actual engine itself, does this sound like its overfuelling?, or has anyone also had this problem?