Got the car out the garage this morning to get it MOT'd today and it ran lumpy and rough till it had warmed up and was fine although hunting slightly at idle. Has been in the garage since the begining of Dec due to the snow and ice.
The only thing I have changed recently is the thermo time switch (brown sensor at the back of the head).
Previously the cold start needed to be plugged in when cold and unplugged when hot and it started no bother.
Am assuming that my idle mixture must to too rich on startup hence the rough idle?
Will be getting setup again once MOT'd & taxed.

 

Could well be different now you changed the TTS, will probably need a look at on an AFR machine and poss a setup/tweak of the idle mixture.