It acted fine at the show, multiple starts and stops, and then did it again on the way home. It has been doing intermittently ever since.
I haven't ruled out valve guide seals, but there's no smoke on high RPM deceleration.
This engine has always has and still runs strong, quiet and smooth, but I did struggle with some detonation issues due to high MAT and timing issues a few months back, it could be getting past the rings, a differential compression test and spark plug will reveal that.
I suppose my big question is how does one check turbo seals for leaks? That would be great if that's all it was. It would also be an excuse to put a more modern turbo in it....
