yes, none are serviceable, but there is an injector relief valve inside where the injector mounts. It has seals and other misc parts that may be affected by a harsh cleaner.

Also under one of the covers (where the injector boost solenoid is there is a thin screen that can get dirty, not sure if carb cleaner will hurt that, its made of either aluminum or steel, not sure but it is fragile.
When i worked for cat we usually did not go into any of those components trying to rebuild or repair them, it was more cost effective when we just verified they were faulty and replaced them.