1992 Chevy Blazer throttle position sensor

Hi i recently replaced the throttle postion sensor after it came up on the computer when i checked it so i replaced it do i have to reset the computer to get the new one to read right and if so how do i do that. im having problems starting it it wont start on its own without a little help from me pushing on the gas to get it to the idle speed then it will stay running on its own.. please help