1986 Testarossa: Engine stalls when cold

Hi Everyone,
My Testarossa starts up easily. However, during the first approximately 20 minutes, the car stalls whenever I push the gas pedal too quickly, whenever I come to a stop sign sign, whenever I slow down too much to make a turn, etc. The car always immediately starts up again when I restart it.
After 20 minutes of driving, the Testarossa never stalls again for the rest of the ride. Any opinions? Thanks!!!!!

 

What version 1986 TR -- US, early euro, early CH?

Is this a new problem (i.e., it was working perfectly and this bad symptom just suddenly appeared), or has it always had this problem since it was last (mis)tweaked-up by someone?

 

Steve,
It's a USA version and I just bought this testarossa in November. A new clutch was installed the month prior to my purchase and I've had the problem since I got the car.

 

Have to say that that suggests that it just isn't properly tweaked-up/balanced. 20 minutes of operation (from cold start-up) is long enough to be in both cold open-loop mode and warm closed-loop mode. Even once it begins to not completely stall, does the RPM significantly undershoot (like down to 500 RPM) during engine deceleration and then "recover" back up to something closer to a 1000 RPM idle?

 

have you checked the 2 auxiliary air valves ( only on K-jetronic )? so they both work equal?