Cold starting an AU S2 6

[4ford]

I can't find any prior posts on this subject...

In recent times I have noticed that when starting cold, the initial running of the engine seems to be on only a few cylinders, and lasts for about 3 or 4 seconds, then normal engine acceleration occurs.
I'm a little concerned, since the engine would be rocking fairly badly on it's mounts during this transition period.

It's pretty consistent, but only when cold, the engine starts normally when warmed up!

Has anybody experienced this rough starting, and what was the eventual fix?

Cheers