Problema com Nissan Axxess Ano 90

Bom para todos e agradeço sua ajuda.
My problem is that I have a Nissan Axxess 90 Motor Ka24 2.4cc 12 valves, which is producing a fault, the problem is that it costs a lot that turns on and when the engine is finally enclosed by the engine when it is accelerated, when I try to accelerate, accelerate, and only decelerate as it drown and I no longer know what to do, a mechanic already saw it and told me that it was the air Change, and follow the fault, Em seguida, altere a bomba de gasolina, pague para limpar os injetores, limpar a válvula IAC e permanecer a mesma e não sei mais o que fazer, por favor ajude.