Stubling issue
 

Hey guys,

EDIT: OK title was a bit of a typo, this isn't about 2 days without a shave:)

I'm new to the 930 forced induction world. I've got an '87 930 that is an awesome car, When the turbo is spooled up it runs great, when it is off turbo it runs great, but easing between the two is where I am having an issue.

If I cruising along at 2500 to 3000 rpm and then try to get the rev's up (and the turbo spooled) it stumbles and billows out some black smoke. Acts like it wants to get moving, but never gets there. Usually I downshift, get the rev's up, and the car takes off like a bat outta hell.

My very uneducated guess is that it is running too rich just before the turbo would be kicking in. Is this a good guess?

Where do I start to investigate this issue? I'm very low on the learning curve of the particulars of 930's so be patient.


Thanks.