I have a 1993, 940. When the outside temp is below 45-degrees (F), the car has a very hard time starting (but it will eventually start). If the outside temp is above 45- degrees (F), the car starts. Someone suggested I check the Intake Air Temp. sensor.

Any ideas on where that is located and how can I test it?

 

well, first make sure that the battery you have is good... the symptom you describe is indicative of just a weak battery more than the sensor. the sensor is located under the 3rd intake rail of the intake manifold, and is hard to get to without removing the manifold...