Idle / temp problem

[con]

Hi Guys
I have a 99 1.0L , 3 CYL Corsa B
I have found that when started fom cold the engine runs low and lacks power.
I have also noticed the outside temp gague reads high by about 3 degs
Could the engine be getting a wrong signal, thus setting the idle / fuel mixture to low?

Thanks for you help

Con