Astra H idle stalling

I've got a Astra 1.6 twinport sxi 2006 now the vehicle will stall when its been idling too long or when the engine has reached a certain temperature it will only ever happen when the car is stationary and sometimes can lose power in first gear when taking off, again when the engine is at temperature, I've recently cleaned out the throttle body however the problem still remains what could this problem be?

also its not bringing up any fault codes even when the vehicle stalls.