when i turn the key nto start nothing happens
Sounds like the "starter solenoid" has gone bad, as you are not mentioning hearing a "click, click, click" noise with no start and you said the battery was good already. As part of the complete check, I would also read codes and check for blown fuses.
i have the same problem , i have a 97 riviera super charge and i had to move the shiftier at the same time as i'm turning the key it took a little bit to get it to catch but it started for me . don't know but i think it might be my linkage .
Search Buick Riviera Questions
Buick Riviera Experts