It may not be an injector as such. In the UK it's known as an air idle valve or air bypass sensor. It acts as a 'choke' for cold starting. I've put a couple of photos on my website for comparison - www.glennsmart.btinternet.co.uk - choose 'Volvo 960' from the drop down menu.
Stand at the front of the car, locate the air filter box and follow the wide bore plastic tubing to the inlet manifold. The air idle valve sits in a rubber ring attached beneath and attached to the tubing. It has an electrical connector plugged into it.
It's very easy to remove.