Nissan Repair: 2001 Nissan Sentra No Start in Cold, fuel pressure gauge, mass airflow sensor

Question
My friend has a 2001 Sentra that used to start fine, but now has an intermittent no start when cold (when it's cold outside and the car is cold; one or the other by itself isn't a problem). It turns over like normal, but doesn't start. The mechanic said this is typical of Sentras, but I haven't been able to find that on the internet anywhere.
It will sometimes start if you keep trying and trying (10-15 times), but not always. I've read through previous posts on here, and have some ideas to check, but what specifically would you recommend? I am assuming the mechanic has checked the typical problems, as it has been in twice already and he is a competent mechanic. More pertinent info: the battery is a few months old, the starter sounds normal when cranking, the mechanic said the engine was flooded the first time the car was towed there.  

Answer
Peter,

You could have a stuck injector and when the computer senses it is cold it richens the mix a bit too much since a stuck injector will allow more fuel into the intake.  Another cause of this problem is the mass airflow sensor going out.  These are intermittent.  You will know for sure when it dies and will not start.  The mechanic can check both of these.  The injectors with a fuel pressure gauge and the mass airflow sensor with a volt ohm meter.