[sp_cs]

Had similar problems on my 3.2 a month or so ago.

After researching on this forum, I suggested to two different specialists whether the CHT was at fault, they both asked if I had plumes of blue smoke coming out the rear when the problem occured. I said no, but the car would jolt at speed as though the rev limiter had been met and then carry on as normal.

Upon checking, i had the old style CHT fitted - once replaced with the later two wire item, the problem disappeared.

Worth checking?

Shirish