Heeere I go again causing trouble for myself...massive studdering problem

[MADMarc]

First, thanks for checking out this thread. I have been trying to find the time to regap my plugs since I tossed in my ebc so that I could take care of what I THOUGHT was spark loss at higher RPMS when 12+ psi would hit. I pulled my plugs and saw that they were at abooout .044 and was reading from several different people that a gap of .032 is solid for 9Bs pushing 14 psi; therefore I closed the gap today. All of my plugs are now at .032 but now that studdering that I felt at 12+ psi happens in lower RPMs and at anything close to 6 and up. The car held steady boost even with the studdering :confused: but I have not been able to check for a boost leak yet (one day off sure wasn't enough to do everything on my list :().

What the hell might be going on here? The plugs, wires and motor have 17k miles on them, but I have not replaced the coil packs so unknown mileage on those guys. Is .032 too close of a gap and I am a fool for doing it? If that's the case then what should I put the plugs at to get the most out of my turbos?

I am using NGK Iridiums...do people commonly have problems with these? The wires are MSD. I am hesitant to go to copper plugs because of their ridiculously short lifespans but if those get me where I want to be I would be happy to swap them out. Any ideas?

Ah...I also have a log that doesn't look too out of the ordinary from previous logs that I have done but I am still trying to learn how to read them. I turned my EBC off (profec spec II) so that I will only be rocking low boost until I can figure this out.

Thanks for any pointers and tips in advance, guys. Please see the attachments for the logs.

[MADMarc]

I don't think it matters at all but I also pulled the EGR tube FINALLY and blocked off the port on the intake and turbo.

[Atrosity]

I recommend BKR7E or BKR7EX Spark Plugs, gap them at .039

I have an extra set of BKR7E plugs and I bought them online if you want them just come on by man you're aren't far away from me, you can't really get them locally also.

http://www.stealth316.com/2-sparkchange.htm

[MADMarc]

Man that site rocks, thanks for the link Eric. What's the difference between the "X" and non-"X" plugs? Temp? How often do you replace those? Sorry about the twenty questions :D Looks like I will go back in there and increase the gap to about .039 as that is close to halfway to where I was and where I am. If that doesn't work out I might just have to swing by after work one night and pick those coppers up.

[Atrosity]

The Ones with a X can last you 30k miles, the ones with out it are good for 10k.

[Austin@STM]

I run these http://www.streettunedmotorsports.com/parts/ngk_bkr6es.htm gapped at about .024 on E-85/9b's. They have been in the car well over 30 passes now plus at least 7000 miles since the middle of last year.

Do you have a wideband? Are you hitting fuel cut maybe?

[MADMarc]

Thanks for the info Eric. Any idea where I can buy them? Also, Austin, are those coppers as well? I will only be swapping the plugs if regapping these iridiums doesnt fix the problem but will be keeping these in mind so long as they are decent all around plugs. How often would those need to be replaced on a bpu car?

[Chris@Rvengeperformance]

advance auto can order them in the next day for $1.79 a piece

I've been running NGK (4930) BCP6ES Spark lately, they are about the same price. Been gapping to .028. I've been fouling out the IK24s putting around town for some reason.

If you go to the parts store ask for the 4930 number or they may not know how to look it up.

This explains some of the part number: http://www.ngksparkplugs.com/docs/tech/partnumberkey.pdf

[thor'svr4]

very similar to my issue.
free bump

[MADMarc]

Thanks for the info, Gump. I forgot to answer: no I am not running a wideband but I highly doubt it is fuel cut even though my nb o2s on my log are slightly subpar, those numbers are nearly identical to what I've seen on previous logs. I do have a new pump and afpr that I want to toss on but dont see much of a point unless I am able to run the 14 psi that I want to and/or upgrade my turbos and injectors.

As soon as I get some time to pull the intake manny again I will regap those plugs. In the meantime, however, would it do any harm at all if I regapped the front plugs to .039 and left the rears at .032 until my days off in (hopefully) a few days?

[MADMarc]

Your 130% low fuel trim will have something to do with it..
In turn caused by the fuel pressure set wrong or somthing else.

One of the oxy sensors doesn't look too good either.

Stock sparkplugs on mine too.

Steve

I was wondering about that trim reading as well. I will just swap out these iridiums for some good ol' copper plugs as soon as I get the chance to do so and re log it to see if anything changes.

[MADMarc]

New plugs and voila, no more problem. Swapped the plugs out to some coppers @ .039 and they work great, thanks again Eric. Next is to up the boost some more and see if I get blowout passed 12 psi. :) Woop!