I was told this on TalkFord, "If the compression test was showing a cylinder was low then to me this would point to a dodgy valve or piston rings and as these engines run to very fine tolorences this low compression could cause poor running and starting problems.".



Could it be that this was the problem all along, as the RAC guy said, and the work on the injectors has been unecessay?



Can you quantify how low the compression would need to be to cause rough running and the engine to cut out?