Over the last 2 weeks ive noticed that my car had bad starts and it would die down for some reason whenever I came up to a light or just in plain stopped the car. I figured the engine was flooding with gas and that the spark plugs might have gone bad. I pulled the plugs last night and they are as black as the night completely burned up. They are the BKR6E-11 plugs gapped to .036. Now my dads friend was tehre who brough over his nissan scanner 2 for the car and we almost got into a fight because he started yelling at me why im using these, they arent made for my car blah blah blah, I mean I know the reasons why I should switch plugs but not enough to put him in his place. I got 2 questions.

1)Why would my brand new BKR6E-11 plugs go out after about 3-4 weeks use?
2)Whats the main reason we change plugs from platinum stock ones which cost about 12$ a piece at the dealership to copper BKR6E-11 plugs that cost about $1.80 each at pepboys. Can someone give me an educated explanation of exactly why the stock platinum plugs wont work.

 

Are those the step colder plugs?

 

i have the same plugs and just changed them out yesterday, they were a little black around the edges but the tip was a light gray. these plugs are only good for a few thousand miles unlike platinum. i think your problem is your running too rich or your 02 sensors are going bad.

http://www.gnttype.org/techarea/engine/plugs.html

 

Actually im running rich, too rich for my liking anyways, and oh yeah just found out yesterday that the o2 sensor thats on the b pipe the one after the cat is dead.

 

running rich will also kill your 02's

 

Also can someone answer what would the symptoms be of a dead knock sensor on a FI max?

 

burns a lot of gas and runs a little slower than normal. do you get 0304 code.
this can also add to your spark plug problem.

 

Yeah those plugs are the one step colder. I thought if you were turbo you needed the bkr7se-11 plugs, since those are two steps colder. :shrug:. Tell him boosted cars use these plugs because they are best for our application. That's what I say, lol. Ridiculous gas mileage, even for a boosted car. ANd as CMAX said, check for any codes. It won't trip the CEL. BTW, which pep boys do you go to in NYC? I usually have cmax bring me over a set of 6 for $8.10 total whenever he is coming around my area.

 

Oh and I don't know if this is sticky material, but this was cool:

 

Tell him that if your boosted you need to use one step colder plugs. Some guys use two step colder plugs depending on power level.

Black seems like your running rich, and you say your running rich so fix it

-matt

 

Yeah well when i boost 10lbs im somewhere near the 400hp range so would 2 step colder plugs be more efficient? At idle im running like 10.5 to like 11.5

 

You should really be at 14.7 at idle. You are running dog rich at idle

-matt

 

lol im running dog rich because i have nismo 555 and a z32 maf and a stock computer

 

well theres your problem right there. you need some fuel management or your gonna keep messing your plugs up and your 02's.

 

I have ran 550's, Z32 MAF, and stock computer for thousands of miles with no major problems. It does seem a little harder for my car to maintain stoich at idle than it should, but my AFR at idle is close enough to stoich. Usually 12:1-14:1. Have not fouled any plugs or o2 sensors because of it.

There may be other things going on than just that he is not directly controlling the injectors.

The rear o2 sensor might be an issue. The FSM is a little confusing to me concerning the rear o2 sensor. In one statement it says it does not directly play a role in AF ratio in closed loop, but in another part it says it does play a role if the front o2 sensors are not with in the proper switching ranges. I would replace it and see what happens.


Borris, the type of plugs your using are fine. Don't worry about that.


Did you ever do a compression check? You last dyno runs were indicating a major problem and that needs to be investigated before you worried about anything else.

Some generations of the Nismo 555's actually flowed 615. You may want to look into turning down your base fuel pressure. Although my stock computer with the Z32 MAF seems to be able to controll the injectors in closed loop well enough, you may just have too large of injectors for your stock computer to do so. Lowering base fuel pressure may help closed loop AFR, but be sure to retune open loop AFR if you try that, because you will run leaner in open loop as well.

But like I said, you need to figure out if there is anothe major problem going on.....300whp on 10psi on your set up is not right at all


Ever get those RunFiles?

 

Oh, one other things that could be an issue is the injector lag time of the Nismo's. It is kinda a shot in the dark and probably not an issue, but Nismo 555's do have a slightly different lag time than what our stock computer is programed for. I run injectors with lag time that our computer is programed for, so that might make a differene. Again, I really dont' think that is an issue but it could be.

 

Actually mike everything went away when i changed the plugs.....kinda wierd, the car at 7lbs now feels like a monster again and prolly running the same numbers as i did when i dynoed the 355 on 7.2 psi, i gotta go back to the dyno and redyno again to see what it comes up with, my af looks like its anywherte between 11-12 across the board right now, but i gotta go dynotune it again next weekendAnd about the runfiles mike, thye never saved them because they though i didnt want them...go figure.

 

Do you have a fpr installed, whats your idle fp?

 

i dont have a frp

 

You should get one

 

what i meant is thats the problem lol, that he is not stock so he has to do some of the things you stated, checking flow etc to get it running optimum.edit. no fpr, no wonder your rich,lol. what kind of fuel pump you have.

 

i have a walbro 255, no fpr, i was thingking of doing a fuel pressure gauge and a frp if its acting up again.

 

you need a fpr with the 255 your gonna be crazy rich at idle