Power problems in a 4y engine

Friends I have a big problem I have a van with a 4y -to -injection engine, it was good until about 4 weeks ago that began to lose power and even I had to re -re -re -re -re -used the engine on my house but when I put first it drown and go out, through the exhaust tube a strange sound is heard not as before when it had a clean sound that can be, a ay city please please

You should be working in less cylinders but you must identify which, to know what is lacking, or measures compression and salts of doubt. That to eat

I am doing well because I don't have a compressimeter, today in the morning he turned well but then tried to walk and drowned and did not want to turn tomorrow I have time I will take him to the mechanic but I would have liked to solve him for myself