not checked coolant sensor yet, is there any way to check these or is it just a case of buying a new one and installing it ?

thermo time switch.....I disconnected the cold start injector and there was no difference, does this eliminate it?

aux air device, I took the pipe off from underneath the throttle body and blew down it, there was no resistance so I'm assuming the aux air device is working as it should be and open when the engine is cold.

Duncan