sure all the converterbolts are solidly in place and the flexplate straight and in its right shape? that would be posible reasons for this in the same way of thinking as my last post here..
Yep, checked that too. The converter is tight, the flexplate is nice and straight.
I would think that if a bolt was loose or the flexplate was bent, the motor wouldn't spin or it'd make a whole lot of noise. But yeah, I checked that anyway. ;-)