1992 Cadillac Eldorado

There is nothing that should be reset. By hard starting, describe the symptom, does it crank fine? Was it yourself that replaced the starter? It should have been disconnecting the battery cable at the battery, raising the vehicle and removing the plastic shields(if they are still there), disconnecting the battery cable and signal wire from the solenoid, and removing the starter mounting bolts. In some cases the exhaust y-pipe needs removed for access to remove the starter. The only thing driveability wise that would have been tampered with, is maybe the ground cable that sometimes accompanies a support bracket at the motor end of the starter. If this ground was not tight, you could have created some concerns.