I have a 99 Volkswagen Passat 1.8 Turbo Automatic AEB engine. I recently did a rebuild on it and ever since I keep getting this code P0301 that says "cylinder 1 misfire". The engine is also running rich and the spark plug in cylinder 1 keeps getting gummed up. I've changed the coil and the spark plugs and the injectors and it helps temporarily but then the problem keeps reoccurring. Any help you could give me would truly be appreciated.