may be irrelevant but may prompt you in the right direction on my zetec turbo pectel management i have high idle issue..so a temporary fix is to disconnect my idle valve WHICH now causes EXACT same issues as you are currently experiencing. I too have too let it warm up with a little throttle.

Sorry not a direct answer but similar issue. Cosworth temp sensor has the same symptoms if you disconnect it. Hard to start from cold. Have you got the right temp sensor for the map?