Problems with my Ford Fiesta

Good my problem is the following I have a 2002 Ford Fiesta and the next fault is the car I turn to it fine but when I start the car for that that has no strength like when a spark plug is burned that has no force but the engine does not tremble or anything I have to accelerate it enough so that it can grab strength and when it accelerates it quite a lot sounds like an explosion or a pus in the acceleration body where I will have the butterfly Spark plug cable coils

How is the engine compression

Czech the catalyst could be obstructed

Nafta or covered air filter ... If the naphtha is covered, it loses power, because it does not supply enough ... and the covered air foul oxygen and does as if it drown ..

Hello, what was intrigued in the end?