will not go above 40 MPH

The problem fixed itself! It was strange..When you tried to accelerate, you could put the gas pedel to the floor and there was no response, like the passing gear engauging. I always go back to the last thing that was done to the car before the problem occured...that was washing it. I don't know if something got wet or if the gas cap was lose? It works fine now, I don't like not knowing what the problem was! Thanks for your time and suggestion!!