First off, pacing is often a bit subjective. What one reader considers un-put-down-able could be too fast to another reader. What one reader considers lovely, poetic prose could be boring and slow to another reader.
You are not going to please everyone. Get used to it.
So how do we find the right pacing for our books?
Aim for a pace that is right for your story—fast enough to keep the reader enthralled, with “sequels” so that they can catch their breath.
Be your own critic in this case. Analyze your story’s pacing and figure out if it needs to be faster, or if it needs more breathing room.
Also depend on your critique partners. Often, an unbiased third party can tell you if the pace is too fast, too slow, or just right.
Utilize Scene and Sequel.
Dwight Swain in Techniques of the Selling Writer says that pacing is dependent on Scene and Sequel. A strong, goal-oriented Scene will increase the story pace because the reader is following the character’s scene goal. The following Sequel allows the reader to catch their breath. By utilizing Scene and Sequel, you’ll keep up a strong pace for the novel.
Length of Scenes and Sequels can affect pace, so make sure you don’t have Sequels longer than Scenes or vice versa.
How long should each be? It depends on your writing style and your story. Again, your own critical analysis and your critique partners can help you with this. Your own read-through or another reader can point out when introspection goes on for too long, or if a car chase scene is getting monotonous.
Make sure to include conflict at all times.
Donald Maass in Writing the Breakout Novel emphasizes conflict to drive the story. Even in Sequels, there is some type of minor conflict going on during the emotional reaction,
Conflict will differ according to your story, your voice, and your genre. For chick lit, conflict might be the heroine’s mother’s nagging. For a suspense, it might be a stalking serial killer. The conflict that fits with your story will be what drives the pace.
A strong conflict during Scenes and a minor conflict during Sequels will keep your reader turning pages, but will still allow them to breathe during Sequels. It will be a good pace that makes the reader stay up late to finish “just one more chapter.”
Look at your own manuscript. What does the pacing look like? Do you have Scenes and Sequels following them? Do you have some sort of conflict, whether minor or major, in every Scene and Sequel?