My 97 850 has 225,000 km and runs great (most of the time). Recently I have found that the car dies on me, briefly, under hard throttle.

It is only 1 in 50 times that it does it, but the car just loses power and coasts for a few seconds, then picks up and goes. it's not abig problem, but something is wrong, and when you are passing on the highway you'd like to think the car can finish off the maneuvre.

I originally thought it was transmission related, but the engine does not rev, so although it sort of feels like a slipping tranny, it is not slipping. It could be boggin down

I could be losing spark, but I do not know why it would be so infrequent, and why it would only be under 60% or more throttle.

I guess it could be fuel related, but again what would cause these symptoms?

Lastly I'm wondering if my wastegate is malfunctioning and I'm losing boost. Maybe the engine spols up, the wastegate dumps, I lose power and rpm, the wastegate closes and then it works and takes off?

My old 740 had a boost gage, my 850 doesn't so this is a bit of a trick to troubleshoot. Anyone had a similar issue, or have any suggetsions?