Trying to de-carbon can't hurt. Carbon messing with valves can happen with port injection but more so on direct injection motors. It is a cheap process with mild-moderate risk. Physical cleaning is more effective than chemical but I've never read a case of long term resolution from either on this forum.
Misfire from carbon buildup is usually from excess carbon on valves causing reduced airflow or sticking altogether. The low compression and port injection pretty much rules that out. Low compression is sometimes a stuck valve but most often bad rings.
Misfire from carbon buildup is usually from excess carbon on valves causing reduced airflow or sticking altogether. The low compression and port injection pretty much rules that out. Low compression is sometimes a stuck valve but most often bad rings.