Is there spark at the plugs when cranking?

If there is spark then you can check the air meter plate movement.
Go to k-jet.org and down load the kjet injection manual so you can see how the air meter plate works.

Be careful removing the rubber billows as it can split easily. It might be better to get to the bottom of the plate by removing the air duct from the air cleaner. Then use a piece of rubber hose or the handle end of a screwdriver to gently lift up the plate. It should move easily and smoothly.

The cold start injector must also work to start a cold engine. You can test it by removing it from the manifold, place it in a can and see if it sprays while cranking. The volume will be much less than the main injectors.