So we bought a new computer for the truck, it's a 1990 5.0 4x4. The old one was having issues with starting and the fuel pump would stay running after turning the key on. So we are on our third ECC and they have all had the same issue. When we put it into drive it won't go except at high RPMs ( or giving it lots of gas, pedal to the floor) and when it is going it seems like its in a high gear. Is there something we are missing on installation, or do we have to have OT specially programmed before hand? Any help is appreciated, thanks.