2004 Sentra rough start/SES light on question?

Alright, I am going to get the code tomorrow for what the light is on for, but in the meantime I wanted to get this thread started for any ideas on what to start looking into possibly tonight and for tomorrow when I start on the car. Basically, for a while now, the car has had an issue where when you go to start it, if you turn the key right over and try and start without allowing some time for the pump to prime it just cranks and wont start. Give it a minute before starting and it fires right up.

That has been going on since we got the car almost but I have had zero time to mess with it. Recently, the car threw an SES light on and it happened after it started one morning but bucked and ran rough on start up until it smoothed out after about 3 or 4 seconds. Then it seemed to run fine. It seems to run fine to me once that rough start goes away, which is intermittent and doesn't start that way every time, but my wife insists it "bogs" on her while driving sometimes. I occasionally feel what could be a slight...very slight, buck/hesitation when driving since this has all started to get worse.

History on the car: It has 111K miles, has new plugs about 5K miles ago, don't know the age of the fuel filter and I will probably be replacing that anyway soon, and the O2 sensors are another unknown as far as age and replacement history. Anyway, any ideas on what this could be or what is maybe normally a culprit before I pull the code tomorrow?

Alright, code was for a PO456 I think...EVAP circuit gross leak I think it read. Anyway, that ranges from anything from the gas cap to vacuum lines to solenoids. Without spending a ton of time diagnosing all of those, aside from checking the tightness of the gas cap, is it likely one thing over another? It has higher miles but it is only 5 years old...still likely to be a vacuum line cracked or something or more likely the solenoid or something along those lines? Any help would be appreciated.

Now I remember why I left this forum in the first place...

all im going 2 say is try a maf mine did the same thing put new maf runs like a raped date.you could try cleaning ur TB four allen screws and its off u will have 2 do a idle relearn

Wouldn't that have set off a code for the MAF than? Also, since it is only once in a while, wouldn't it more likely be an intermittent issue from something in the EVAP system as the code suggested? I will clean the TB, but the car gets good gas and regular maintenance. The fact that it only does it once in a while and does not run like crap for more than a few seconds before clearing out/fixing itself is what has me guessing.

if the maf is bad it could set that code off

the symptoms of maf sensor being off is it usually searches for idle, like it gives a little gas and then drops off at idle

the evap circuit is read by the maf yes so i would pursue this

however i must say that your earlier description sounded like the fuel pump is going bad. or the fuel pressure regulator.

even if its working if the pressure is not up to specs it will flood.


it will work most of the time and screw up some of the time.

Even when the fuel pump is not working right your car will run and it will cause stumbles.

Believe it or not this is one of the easiest fuel pump jobs in the world.

I need to get the book for this car, but for now, how hard is the fuel pump/regulator replacements? What all is involved? I have been meaning to replace or at least test this thing for a while now as the issue with the no start right away sometimes has been a real pain ever since we got the car...just haven't had time. Now I need to make time.

your model is different than mine

I have a b14. Ive also had a g20 though so I feel like Im getting the nissan vibe

Id just say replacing the fuel pump is one of the easier jobs on these cars as far as fuel pump replacement goes.


I think its worth buying a fuel pressure guage and harbor freight for about 20$

I think its a valuable long term tool anyway for diagnosing vehicles.

A lot of people get confusing symptoms with the fuel pump going out so I think its really important to a eliminate it

you know what bad spark plugs can cause flooding too.

Its very difficult from here to tell you what Id do. you should go ahead and look up your code though on the internet

I have a feeling that code in troubleshooting might ask you to check the fuel pressure anyway but I havent looked it up myself.

ya actually that code can be caused by the engine flooding.

I have to be psychic from here but I couldnt give you any intelligent advice til you tested the fuel pressure.

Needing to let the pump work a few seconds to get pressure sounds like its gummed up to me. that should be the end of it right there.

The regulator can be gummed up too i mean it can be the whole cause but the first diagnosis is the fuel pump

I think i have advice on the one to buy too if u find out its bad.

just cranking it when fuel is pumping and letting it evaporate when flooded will set that code off in itself doesnt mean anything is wrong.