I have a question concerning checking a compression check on a 12 vlv. The reason i'm askin is the blowby has a pattern to it that matches a stutter at idle. Would this be broken rings, or burnt valve? pretty sure that a compression check would pinpoint which cylinder, but what would be the cause. Any advise would be appreciated.

 

have you replaced or had your injectors checked or cleaned?
a weak injector will through the timing off in one or more cylinders.