When i try to rev up my engine, it goes strong to like 2.5 then falls, it will go back after a second then fall back. my car's top speed is 38 mph. when it climbs a little higher the engine cuts back.

does anyone have any idea of what is going wrong? i appreciate any input.

 

check your mass air flow sensor to make sure its plugged all the way in and none of the wires are broken out of thier holders if you floor it in neutral does it not go over 2.5K