Interesting thing about cold start valves is that they don't do much in Florida. They only operate below 59 deg. Cold starting is almost never a cold start valve (in Florida anyway). I don't remember how accessable it is but I would unbolt it and pull it out of the manifold with the feed line attached and then try it cold. It should work for 1 to 12 seconds WHILE cranking depending how far below 59 degrees it is.
The first thing I would check would be the EHA current during starting (but I live in Florida). You should get 50-80ma current with the combined effect of starting enrichment (at all starts) and cold enrichment (varies with engine temp). If you have a bad OVP relay or fuse you will have zero, zip for current.
Bosch Master, ASE Master, L1
33 years MB technician