If the tension on the serpentene belt is off, will it cause a choppy kind of idle? Are there marks down by the tensioner to guage the correct tension? Any info would be great.

Gene

94 Z28

 

It might if its not charging enough but I would think you would see that in the guage.
If you think its suspect just change the tensioner, they are cheap and I reccomend changing it after about 100k anyway.
If you can get a long screwdriver to push on the tensioner (be careful) and see if that changes anything.