Hi, I have a 2004 Sentra, and about once every 5 starts it takes 4-5 seconds for it to fire. It cranks fine, but just won't start quickly. I have read to check the Fuel Pressure Regulator, or Fuel Pump Check Valve, but have not done this yet. Is anybody else experiencing this problem, and found a solution???
Thanks a bunch

I have an 03 Spec V and I had a similar starting problem. Sometimes(especially after long trips) my engine would turn over about 5-10 seconds before it would fire. Also when it did fire, it fired rough. After three trips to the dealer, they finally replaced my fuel pump since it was under warranty and I haven't had a problem since then. I've heard about this before, so they must not have all the bugs worked out in the fuel pump they are putting in the sentras.

It's the fuel pump. Before trying to crank, turn the key to the first notch and allow the fuel pump to prime. It should fire up with no problem.