Is there such a thing? Can a story have too much tension?
One way to check is to read a story or see a movie that is a thriller. Try to choose something where the action starts at the beginning and never lets up. A good example is the movie Ben is Back starring Julia Roberts. The tension runs from beginning to end, with no let up. There is no scene in which the characters are not frightened or concerned or worried or frantic.
As a viewer, I was in overload after twenty minutes. I wanted some sort of release. There is one scene in which it was possible to have that release, but the camera focused on Ben and what he was feeling.
Your task is to write a scene in which tension is constant. Choose a setting that is appropriate for that level of tension. It could be a bank robbery, a kidnapping, an attempt at escape, running from evil (or from the law). Keep the focus on the emotions of your main characters.
When you are finished, reread or ask someone else to read. How do you feel as you read? Is there too much tension or the right amount considering the setting?
Next rewrite the scene with moments in which there are lighter actions. Then reread.
Which version works best?
Have fun with this one.