Did you put the "bad" TBI on the "good" engine to see if it exhibits the same symptoms?
Did you check the coolant temperature sensor? If it's bad it might be telling the ECU that the engine is already warm, even though it's not. Then the ECU doesn't send a big enough pulse to the injectors to run the engine rich enough when it's in that warm-up phase, resulting in a weak engine which results in a stall.
Does this engine have an air temperature sensor? That could also do the same thing, but not as likely.
btw... you should stop referring to them as 'carbs', as that gets confusing. You have a Throttle Body on the engine.
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