A good rule for writers: do not explain overmuch. --W. Somerset MaughamAssume the reader has a brain is good advice indeed. When you go into too much detail on things that don't move the story forward, that explanation stops the story. For example, don't tell me every little detail about how the character exited the room unless he jumped out the window and you want me to wonder if he survived.
When reading fiction, readers are capable of filling in huge blanks. If it adds to the story and to the tension, include it. If it doesn't, leave it out.
Sometimes it's not so easy to tell what is important and what is not. You'll have to be the judge of that, but if you want your plot to move, then don't slow it down with minute explanation of what is not important. Rather, fill it with what reaches into the reader's gut or heart or mind to captivate them.