Thread: sputtering at startup on 01 b15 SE

I own a 2001 Sentra SE with a sr20de. I checked my plugs today to check my compression and i noticed that #1 plug is white which is running lean and the other 3 have a greenish tip on the end of the spark plug and looks to be cracking or something like im getting pre-igintion or detonation. Im also running 19* timing with 93 octane. Im running ngk iridium plugs. I have replaced my button but not my cap yet. I have upgraded wires but its been awhile since i replaced them. Do you guys have any idea if this would cause that kind of problem? sounds like a subaru but once you give it a few shots of gas it quits.

How did you set your timing and are you sure it is actually at 19*? Did you try and bring your timing back a couple of degrees and see if that helps. Also OEM wires are usually best.


http://www.theultralightplace.com/sparkplugs.htm

Is the porcelain cracked? Ya sounds like detonation or overheating.

Edit: I guess I didn't read your post properly. Sputtering on start-up sounds like a fuel problem not a spark problem. Could be clogged filter but with Nissan could be a fuel pump. But I would still try and bring the timing back a couple degrees and see if that helps. I have the same car as you.

Not sure if you have the FSM for your car or not but just in case: Index of /FSM/Sentra/2001_Sentra

No i sure havent its been set at 19* awhile now. I have obx spark plugs wires that are 10.3mm. I still have stock ones but not sure the exact mileage.

No the porcelain isnt cracked from what i could tell. Our cars doesnt have fuel filters atleast i coudlnt find it anyway. I have a walbro 255lph with a nismo fuel pressure regulator set at 38psi im confused why it does this

The fuel filters for our car are in the fuel tank with the pump. Nissan claims they are lifetime filters and don't need to be replaced but I've heard otherwise. Are you getting steady readings on the FPR?

well i put the old screen or filter whatever you wanna call it back in the tank because the one that came with the walbro wouldnt fit but i still might have it layin around somewhere. Yes its pretty accurate and mostly stays 38 at idle but once you give it a shot of gas it goes up some but unsure how much.

If one spark plug is way off of the rest it sounds like a fuel problem on that cylinder.

Now I'd say a lean showing plug also can mean it is getting too much fuel there but I wasn't able yet to reproduce that awkward situation.

If it is not fuel/ injector issue, it might be a spark issue (easy to check I suppose) and it also could be that your intake has cracked or some vac hose is leaking really bad.

A compression test would not hurt. If you can do that, go from there I'd say.

I got 140 on all cylinders and i didnt even warm the car up i forgot

Have you figured anything out yet? 140 PSI for a cold compression test for the RR SR20DE is a pretty good number. The compression on those motors should be 185 with a minimum allowable limit of 156 PSI, but this is with a warm engine so you are fine. Plus you are the same across the board so HG should be good.

It is hard to say if it is fuel or spark but if you are sure that your FPR is reading accurately then your pump is probably good and you can them move on to checking your spark again. If I were you I would put the car in timing mode and set it back to base idle of 15*, change the spark plugs, clear the computer with a scanner, even if you have no codes coming up and then start the car and see if it runs better. If it still doesn't run better you can check and make sure your injectors are working properly as per the Field Service Manual, that I attached in my second response.

Beyond that it may be something simple like a dirty/clogged or faulty EGR valve. Seems unlikely to most but it it possible. Yes, the EGR is not operating on start-up as it doesn't do anything until the car is warm, however, if the EGR is dirty/clogged or faulty and not shutting properly it might cause some start-up or idle issues because of a vacuum leak. Also a non-functioning EGR on that engine will cause the engine temperature to rise and NOX gasses will likely be higher and can cause detonation, especially when you have already advanced your timing a few degrees. Just a thought!

Hope I have helped. Maybe somebody else has better suggestions!

Good luck and keep us posted.