My 2003 Nissan Sentra floods when I try to start when it is humid out. What can be done to fix it?

Vapor lock

There are several possibilities. I assume the service engine light is on, indicating the engine computer knows there is a problem. If so, get a readout of the code; this will help you narrow down the problem area.

One possibility is a blown fuel pressure regulator; this can cause hard starting and flooding. Often, when the engine is cold, you can smell raw gasoline in the exhaust. Fuel injector problems can do the same thing, and could possibly cause poor performance. The engine computer would flag mixture problems.

Another possibility is a carboned-up EGR valve or exhaust manifold.

In very humid or rainy weather, a failing oxygen sensor causes poor performance, but usually does not affect starting.

Also, in humid weather, especially if there is precipitation, a failing ignition coil will cause all of these symptoms. If you have had excessively worn spark plugs, the wide gaps can cause coil breakdown as well as poor starting. That will set up this failure mode. You may get misfire or other ignition codes from the engine computer.

Visit the on-line store, known as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem. 2003 Nissan Sentra

Quality and good one.

distriutor cap or a bad wire try spraying wd40 on the cap

I have the same problem with my 2003 nissan sentra gxe. I don't know about under the hood, but I was told that the gas filter needed to be changed. Something's wrong with the gas intake to the engine. I had it "fixed" but it still does it a little bit everytime.

you hit the nail on the head ,cold and silicone chips ,they do not like the cold weather they can be temperamental to say the least ,as for finding the faulty component you will need an identical car that works ok ,then when yours will not start try swopping bits till you hit the one causing the problem.or sell it for a nice manual diesel version,

Check out the catalytic converter, might be plugged up. I have seen some cars that will run fine, and like someone threw a switch the car acted like yours, no power, would not rev and died. Later when cold they would be OK for a while then just get worse and worse.

try replacing the crankshaft and camshaft sensers, my 2004 sentra spec v had the same problem.It cost me $122 for both the sensers and can be done in 20mins

you likely have a bad cap and rotor when the weather gets humid and or very cold moisture can get into the cap and cause a crossfire condition(firing on mulitple/wrong sparkplugs) and will prevent it from starting.My 1996 chev silverado has done this to me 2 years in a row on one of the coldest nite of the season and both times a cap and rotor fixed the problem.(the first time i bought the cheapest one I could find...not so cheap now though!)
Hope this helps!