Stuttering problem when car is cold??

For some reason, my 91 talon is stuttering when the car is cold. It seems to get better and eventually go away as the car heats up while driving. I was having an idle surge also, so I put a new temp. sensor in and adjusted the BISS screw, which seems to have fixed that problem. It starts stuttering when the boost starts to kick in, but at idle it is fine. If I ease into the gas without the boost it is fine also. But as soon as the boost starts to kick in, the car starts stuttering really bad. The stuttering gets better as the car warms up and will eventually stop if I run it long enough. I have a manual boost controller from bushur racing. Is it possible I have the boost up too high? It is set to spike around 15. The spark plugs have been checked and seem to be fine also. Any help??

1992 Eagle Talon Tsi AWD For Sale

1992 Eagle Talon Tsi AWD

Car is in good condition with a 6-bolt motor and 4-bolt rearend. New brakes, 2 1/2" buschur exhaust, k&n filter, newer tires, enkei wheels, boost controller and gauge. Engine is warranty rebuilt motor with about 25k on it. Chassis has about 110k miles on it. 5-speed trans. Black. Some hail damage.

Asking $3200 or b.o.

tazdevil69@mchsi.com