Nissan Repair: hard to start in cold weather, fuel pump relay, nissan maxima

Question
I have a 1998 nissan maxima. I recently (today) had it tuned up. New plugs,fuel filter,air filter and replaced belt. It still takes 4 or 5 tries at getting it to start. The mechanic thinks it is the fuel pump. I disagree because it runs fine, starts on warm days,etc. It does this when there is a difference in the temperature outside. Can you help me on my next thing to checjk out, Because I know there are a lot of sensors on this car. Thanks.

Answer
Debra,

The cold start sequence seems to be defective.  First, and cheapest, is the temperature sensor that tells the computer to go into cold start mode.  It acts like a choke and if it is not working the car will take several times to start.  Depending on your model you will have a temperature sensor for the gauge or light and another one for the fans and one specifically for the computer to sense when the engine is cold.  Most of the newer Nissans use one for the gauge and one for the fans and the one for the fans do double duty letting the computer know to richen the mixture and to increase idle until the car warms up.  That would be the first place to start.  Another cause could be the fuel pump relay being old and it takes several attempts to get it to make contact.  Both the temperature sensor and the relay go for under fifty bucks each plus the installation.