I bet those pistons and valves are nice and clean now.

 

did you ever figure out what it was?

 

Sounded to me like it was on way more boost then he thought. Higher then normal fuel pressure under full boost and still going lean, its prolly on 15psi injectors maxed and fuel pressure is higher then normal. Only way the fuel pressure raises more then normal is if there is more pressure on the fmu then normal.