You will need some log with eehack during startup, maybe something is out of spec.

Than figure why it dies, lack of fuel or air or extra fuel, When cold fuel evaporates slower, and it may peg down after crank. Check for leaking injectors, vacuum leak or crap spark plugs.

Getting the throttle to 100% will cut fuel at cranking.

Fine tuning the prime pulses will get you spot on. There is a scalar that might need changing too, to allow for more fuel at cold temperatures.