I want to replace the engine coolant temperature sensor.  I am having
what I call stumbling start ups early in the morning.  Does not do it
except if the car sets up overnight.  It is noticeablely less intense
in the stumbling based on the higher temperatures outside.  Worse in
the winter.  When it is in the 30's the car will choke down then
restart with no problem.  Acts like it is not getting any gas then it
goes on and you don't have any more trouble.  Nothing shows on the
electronic checks that have been done.  Nissan replaced a sensor in the
rear of the car but that did not do anything.  I have also replaced the
fuel filter in the tank.  Nothing.  It got better after we replaced the
started because it went bad, but I think that is because the weather
just got hotter.