I am losing compression into the crankcase. Can this be a possible injector stuck open?

 

no...and how do you know you are loosing compression? Rings or valve issues.

 

The shop that is at has done a compression test and said that I am losing compression into the crankcase. They are telling me the piston melted but I am not convinced. It was running perfectly normal then all at once it started running rough and puffing white smoke.

 

Heads are gonna have to be pulled. White smoke can be an overfueling issue or coolant as well.

Either way the heads need to come off to take a look.

 

Probably cracked a piston. What cylinder is it that is low on compression?