could the fuel injectors or fuel pump be the reasonthe car is bogging out and shaking?

around 40mph the car beigins to bogg out,and seem like its going to die,and car starts shaking and noises like knocking sound
as you accellerate the speed this stops.it doest do it all the time but more and more often recently,also it over heated today for no reason.it was paeked for several hours and we just began to drive when it did it.