ok so i have a few questions on my 97 blazer 4x4 the engine will sometimes bounce up and down during idle (400-700 rpm) and the rpms will stay at 1000-1500 rpms and will slowly die back to idle rpm so is it something with the computer or the cable sticking?

 

This could be caused by a sticking IAC valve. I would remove the throttle body and give it a good cleaning, removing the IAC valve and cleaning it and its bore as well.