trouble with shifting gears on 1993 Ford Tempo

auto trans-very low mileage, won't shift into 2nd until around 25-30 MPH and into 3rd until around 50 MPH....RPMs are going crazy by that time.....just had a new filter and trans fluid replaced and they added a conditioner, no difference. Could it be the speed sensor or a vacuum problem?

Asked by for the 1993 Ford Tempo
AAmco will test it free..