91 Cavalier engine surging

My daughter has a 91 Cav 4cyl and her check engine light has been coming on for a few days. Now she says the car will suddenly accelerate on it's own (pulls the gas pedal right to the floor from under her foot!) and zoom up to about 60 MPH for a few seconds at a time - then back to normal. She usually has two little kids in the car and I need to fix this ASAP. It also is using WAY too much gas. I'm thinking engine sensor(s)... any suggestions?

Thanks,
Scott