2.2 direct cold start

Hi all

I wondered if anyone can help. I have a cold start problem on my vectra 2.2 direct. When you start the car from cold it has no high tickover which then comes down after a few seconds on getting warm and idles normally. It now just starts and goes straight to idle there is no higher revs as you would normally get when a car is cold.

Sensor maybe ?,. Any advice would be great thankyou