Nissan Repair: hard starting, common denominator, cold start

Question
my wife just bought a 98 maxima and it has problems starting. the former owners said it sat for about a year so i changed the spark plugs and fuel filter and still having problems and it is harder to start for the first time of the day. i have had a few people look at it and most say it is the ignition switch, and a few say the fuel pump. it turns over but it always takes awhile to start and now since it has got cold we cant start it at all. and when i turn the key on i can hear the fuel pump make its humming sound so what is your advice. thanks justin

Answer
Justin,

If the car is hard to start or will not start I would check the fuel pressure first since that seems to be the common denominator.  If the pressure is fine then go and look at the cold start sensor.  This is a temperature sensor that sends a signal to the computer to richen the mixture until the car gets warm.  Check these out and email me back.  Oh, there are no codes set, right?