1995 850 Turbo: has normal low boost but won't go to higher output above 3000 rpm,no knock retard, temp normal etc.,etc.,etc.,.....
[The ECM is to allow more boost provided there is no knock retard or enrichment,the temp is normal, rpm is above 3000 and a couple other requirements I don't recall right now.]

I recently had the head off to replace a blown head gasket {no cylinder damage, in fact it still had factory cross-hatch in cylinders even after 155000 miles!} and when I completed the job it ran great, tons of power, all was working great.Then after about 20 miles of driving I noticed no more High output. I assume the ECM is the culprit after finding no hoses or connections at fault. I have seen this once before on a customer car but was unable to diagnose as the customer moved to another state the day after he brought it in for repair. I am currently leaving the battery disconnected overnight to reset adaptive and clear memory. Anyone out there seen this before?

[the ECM also prevents high boost in reverse, winter mode and forward gears when brake is applied]