An MFi setup should not be used without the coldstart valve plugged in and working.

Your system will need to be setup and in tune for the cold start setup to work correctly.
Most people blame the injector for their engine being out of tune and disconnect it. You should have your engine setup to cure the problem not randomly disconnecting sensors or components etc.

There are many reasons why the engine would do this on start up.

But by disconnecting the cold start valve will not help you find the reason and easier.

Take it to a tuner and have it setup correctly or do some research and read a setup guide which i have put together for people like yourself.

Regards