I need help with my Kia Avella 2

Hello friends I am new in this forum and I am looking for help regarding the problem my car has.

The problem of my car is that when I drive at any time I hunt and lose strength and at the time of accelerating the car does not accelerate but loses strength and stops
there that does not stop and recovers
that happens again several times during the section that I go with my car.
He took it to a workshop made a complete washing to what is engine spark plugs and sensors and I don't know what a problem can have.
I hope you can help me with my problem thanks

my car is a Kia Avella Delta 2
year 1998

Electronic catalytic

how the car behaves in idle.

Only one fact comes out slowly but if it comes out, you say that when going running, sucks, I imagine that you mean that it loses strength, it knows that it is a Terracan, almost with that same failure, change filter, spark plugs, check land, and at the end of I had to change the detonation Singor, and there was the nail, but I prefer that the flow This clogged by dirt, psale carbucleaner, and let it dry, have what happens ,,

That is what happens to me several people have told me that it can be a sensor so I will review all that
thank you very much for your time then I tell you how it was.