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my R33 gtst sparkpugs keep dying - wonder if there is a setting related to link ecu?

anthony mcgrath

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hi all

i've had my car mapped for a good few months now - its been running like a missile it really has and has been a great daily driver as well as a ferrari slaying hog!  It fires up every day without issue and gets me to work and back as well as out for spirited drives!  loving it!


However i've gone through 3 sets of spark plugs since it was mapped earlier this year.  When i take them out they seem to look okay - nice and tanned (not black or chalky white and peppered) and on WOT with link logging the AFR is spot on.  I have noticed some insulation with scuff marks on them though.  The car seems to do this every couple of months - it runs great but progressively gets worse.  I've swapped Crank Angle Sensor (CAS), coilpacks and sparkplug types (iridium to copper and back again) and the problem still seems to periodically come about.  I've changed fuel types from tesco99 (which is was mapped on) to Shell V power but the problem still persists especially in 4th gear higher up the rpm range.  i get some slight misses but occasionally a good couple of harsh misses that make me come off the gas quite quickly and slow things down.  As the sparkplugs die more and more it eventually gets to the point where i cant WOT it in low boost mode (1 bar on a GT3076R turbo... high boost is 1.4bar and its insane!) without it spluttering at 5000rpm.


I'm kind of at a loss now as to what it could be really.  I'm posting up on here because i'm wondering if the link plugin ecu needs something inline with the coilpack signal wiring or something coming from the ecu?  I only ask that because years ago i had a map2ecu piggyback fitted (yech!) and that needed 220ohm resistors inline with each coilpack signal wire i think.


also would there be any options worth looking at first to try and isolate this issue?  I know thats like asking to find a needle in a haystack with the link ecu's many options but somewhere to look first.  I've seen a few ppl now with link ecu's and they have the same issue at 5000rpm so i'm beginning to wonder if the link ecu is having some issues somewhere with the skylines maybe?


is this anything ppl have rectified or experienced similar issues with on their link systems?




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Hi Anthony.

As far as I am aware, there is nothing that the Link requires extra as it is only a low current negative signal being sent to the ignitor.  The problems you experience with your spark plugs have a few possibles ranging from detonation, to super rich warmup and a few things in between.  Have you tried using different temperature spark plugs, and what are your AFR's reading during the start/warmup phase?  Tis a strange one.

Also, can you define a bit clearer 'I have noticed some insulation with scuff marks on them though'.


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Anthony mcgrath  as a rule of thumb for every 100 ps ( horsepower ) above the stock  you have to use one grade colder sparkplugs than what the car had stock .

What you describe looks like that your plugs cant handle the stress of extra pressure - heat  or what Jurgen said . You can find  a type of plugs that is Platinum + Iridium  and have the nice longevity because of platinum  plus the nice spark  cause of iridium =)

Stay away from cheap plugs

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  • 2 weeks later...

I would put money on what you are experiencing is as the spark plugs wear off the sharp edges due to spark erosion (normal wear) the ignition is no longer able to fire the spark plug.

The answer is here


A cheap way is to use smaller spark plug gap but cold start fuel econ and idle etc all suffer with smaller gaps.

The best way is to upgrade the ignition and I dont mean aftermarket stock fitment  coils.

CDI Ignition is amazing and you will be able to run a 1.1mm gap and never missfire again.

Its not cheap but you will never have your plugs out again.

There is nothing wrong with using a cheap plug esp the NGK Vpower range which you can buy in NZ from Speedtech and others.


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  • 1 month later...

hi guys

big thanks for all your comments i haven't had chance to check this thread of late (my wife is expecting our first heh!).

anyways i've been running normal NGK copper 7's on my car and its almost like clockwork - 6-8 weeks and they break down.  If i remove them they seem fine visually - fairly even burn rate (altho cylinders 5 & 6 at the back seem a bit whiter a little bit).

once i swap the plugs for another cheap set of copper 7's the car runs sweet - bonkers in fact for about another 6 - 8 weeks depending on how much/hard i drive the car.

@Jurgen - thanks its comforting to know that the link doesn't require anything more - i guess this is proven by the fact that when my is running sweet its REALLY running sweet - smooth idle, smooth power delivery all the way to redline in all gears.

@Mark/Dobsons - cheers for your advice guys - i cant afford a CDI ignition system - it probably amounts to £500+ by the time i've bought all the bits i bet.  I'm gonna try to sort this with what i have because there are guys running far more power than me on the same setup and they dont see any such issues :/


there are a couple of things some skyline owners running high power (500+) have done that have worked for them - here they are...

-sparkplug gap as you guys have indeed mentioned - i'm gonna try gapping to 0.5mm and see what happens - car never gets driven hard cold anyway.


-run colder plugs (heatrange 8's) -  not tried copper 8's in yet - gonna give them a shot gapped to 0.7mm?


-change the coilpack rail from metal to a homebrew plastic/acetal one.  Apparently the metal rail can be conductive and spark strength if it escapes the coilpack somehow dissipates through the metal coilpack rail.  I'm gonna try the acetal one and see if anything changes.


whatever the issue is it really is like trying to find a needle in a haystack now.

ps apologies for my very late reply!



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Hi man, I'm on a couple of other forums you post on as 'Lith'.  Good to see you are still enjoying it - must be a lot of fun... I miss my old GT3076R setup.

What gap have you been running up until now?  Do you have any pics of a set of plugs which have come out of the motor?  I always ran .8mm gap with mine and never had any issues.

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hi guys not sure if the pic of the plugs attached to this post or not but here's hoping heh!  its from a previously removed set but tbh the other sets aren't coming out much different at all which is confusing me all the more!

oh worth noting - i double checked the boxes (yep i keep all the previous sets of plugs and boxes with install/remove times) and they are actually copper 7's NOT 8's.  I've got a set of copper 8's to go in next and some iridium 8's too - i'm trying to eliminate all options really.

@Jurgen - i'll try gapping to 0.6mm with the current set of plugs and see what happens.  Regarding your first post about asking what the spiderweb marks are on the insulation it might be visible in the attached pic?

@Daniel (Lith) yep seen you posting on some other forums in the past :)  its a bonkers setup - i'm hoping to get it on a track in the new year to see what it does but it scares me now on the road - you really need to drive for yourself but also have eyes for the ppl nine cars up the road that you'll be on top of in no time if your not careful!  more than enough power for the road i think!  It kept up with a bmw M5 V10 E60 or something only recently and that was with a poor geometry setup (which was affecting speed hugely with the enormous 6 degrees of toe IN on the front) and a downpipe that was half hanging off so with some fine tuning and a bit more boost i reckon it'll embarrass cars like that!

regarding gap its been running the standard 0.8mm gap on the copper 7's - i'm gonna try and regap them tonight to 0.6mm like Jurgen says and see what happens.

My plastic came through too so i'm gonna try and make the new coilpack rail from it this week too!  it seems to have fixed alot of ppl's misfire issues (whom are all running correctly gapped iridium plugs suited to their application and splitfire coilpacks) but they still get misfire like me.  Its a weird one but for the sake of 20quid on a chunk of plastic board and some fun time with the jigsaw and drill i thought what the hell :)

will post back my findings guys thanks!

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  • 3 weeks later...

Isn't the coild pak supposed to be earthed anyway ie the return side for the spark back to the coild body, if you mount it on Plastic doesn't that detract from the coils ability to provide the circuit back to earth, as well?

Also with the coil packs , I initially tried coating mine in  a clear coat of Nail polish of all things. (mrs didn't mind because she didn't know haha)

In the end I just fitted splitfire coils and all my misfines etc on full boost  just disappeared. Running 7 Series Iridium plugs

no more worries so far.




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