Jump to content
SAU Community

Recommended Posts

Hey guys quick question, i know this topic has been covered a thousand times and believe me when i say iv been researching for hours!

But im still having some trouble :/

Well today i changed my spark pugs for the 1st time since i bought the car (Recently purchased 3 weeks ago). It had PFR5G-11 in there and i changed to copper plugs BCPR6ES .8mm gap.

Anyway went for a drive and on boost it missfires from 3.5 to 5 thousands revs (a popping noise from the exhaust)

The car is running on 15psi with a highflow turbo and splitfire coilpacks. Didnt have any problems with the previous plugs, so i checked what the PFR5G's were gapped but wasn't sure because every plug had a different gap size :blink:

I read in someones post that :-

- weak coilpacks require a smaller gap so that there can be spark, but itsn't so good for performance (but can eliminate misfire)

- coilpacks with a strong punch can utilise a spark plug with a larger gap (due to being able to create a bigger spark over a larger distance) and can increase torque"

My question is that if thats true what gap size should i be running??

Any help would be much appreciated

Link to comment
https://www.sau.com.au/forums/topic/355444-missfire-question/
Share on other sites

Um I'm pretty sure the bcpr6es are not copper plugs not 100% but I am pretty sure the bkr plugs were copper plugs I currently run the bkr6e ones in my car they are copper v plugs and I have not had issues with them I tried running the bcpr6es plugs and I had flats spots and miss fires as you described I dunno y but my car did not like them

Um I'm pretty sure the bcpr6es are not copper plugs not 100% but I am pretty sure the bkr plugs were copper plugs I currently run the bkr6e ones in my car they are copper v plugs and I have not had issues with them I tried running the bcpr6es plugs and I had flats spots and miss fires as you described I dunno y but my car did not like them

hmm what gap size, boost and coilpacks are u running? from what iv heard the bkr6e plugs are abit shorter in length to the bcpr6e.

hey mate the BCPR6ES .8mm gap plugs you have are ok. i run them and countless others. if they are missing at .8 then the problem likely isnt them. but maybe the coils are weak and the previous plugs were gapped lower therefore didnt missfire. you could try gap to .7 and see if its better. the difference between .8 - .7 at 15psi is probably minimal but if it fixes your miss then you could try it out 4 a while. have you read the DIY about insulating the coilpacks to prevent missfire?

http://www.skylinesaustralia.com/forums/topic/119403-how-to-fix-missfire-problem/page__hl__coilpack

Edited by t_revz

hey mate the BCPR6ES .8mm gap plugs you have are ok. i run them and countless others. if they are missing at .8 then the problem likely isnt them. but maybe the coils are weak and the previous plugs were gapped lower therefore didnt missfire. you could try gap to .7 and see if its better. the difference between .8 - .7 at 15psi is probably minimal but if it fixes your miss then you could try it out 4 a while. have you read the DIY about insulating the coilpacks to prevent missfire?

http://www.skylinesa...e__hl__coilpack

I thought that having splitfires i didnt have to insulate them, but worth a try i guess.

Thanks for the help mate, much appreciated :thumbsup:

hey mate the BCPR6ES .8mm gap plugs you have are ok. i run them and countless others. if they are missing at .8 then the problem likely isnt them. but maybe the coils are weak and the previous plugs were gapped lower therefore didnt missfire. you could try gap to .7 and see if its better. the difference between .8 - .7 at 15psi is probably minimal but if it fixes your miss then you could try it out 4 a while. have you read the DIY about insulating the coilpacks to prevent missfire?

http://www.skylinesa...e__hl__coilpack

hey man i siliconed the coil packs and re gaped the plugs to .7mm and shes all good now :D

hey man i siliconed the coil packs and re gaped the plugs to .7mm and shes all good now :D

good to hear its ok now, next time you change em id run them back at .8 as i would imagine it was more the silicone that fixed it. if increasing the gap brings the prob back then likely a coil but you could keep running .7 til it gets worse or you up the boost and have to sort it out.

Trev :thumbsup:

  • Like 1

I had a missfire issue after 4500rpm+ with BCPR6ES .8mm. I bought BKR7E .8mm with the 'V groove' and now running perfect.

Running Splitfires too..

Your the second person who said that...thanks il keep that in mind next time i change the plugs :thumbsup:

  • 4 weeks later...

He says that because of the host of issues that come with adding extra boost and assuming the ecu can happily deal with it. It you changed your ecu and had a tune, your power and fuel economy would both increase, possibly dramatically.

Bcpr6es and bkr6es are both copper plugs.

If insulating helps then your splitfires may need replacing in the future. I'd go with yellow jackets, they're a lot cheaper and come with a 2 year warranty.

Is 6 the right heat rating for 15psi? I'd have a good look into that, esp if as you said two people have moved from 6 to 7 with v groove and found an improvement.

There is a mighty long thread on spark plugs worth a read, here

http://www.skylinesaustralia.com/forums/topic/104405-spark-plugs/

Edited by Galois

He says that because of the host of issues that come with adding extra boost and assuming the ecu can happily deal with it. It you changed your ecu and had a tune, your power and fuel economy would both increase, possibly dramatically.

Bcpr6es and bkr6es are both copper plugs.

If insulating helps then your splitfires may need replacing in the future. I'd go with yellow jackets, they're a lot cheaper and come with a 2 year warranty.

Is 6 the right heat rating for 15psi? I'd have a good look into that, esp if as you said two people have moved from 6 to 7 with v groove and found an improvement.

There is a mighty long thread on spark plugs worth a read, here

http://www.skylinesa...05-spark-plugs/

Well today i changed my plugs to bcpr6e the v grooved with .8mm standard gap plug( got them for free off a friend so thought il give them a try), and i had no missfire. I guess insulating the coilpacks solved my missfire.( when i insulated my coilpacks i also gapped the plugs to .7mm at the same time, not knowing if the gap size or the insulation solved the issue) Would i still need to replace my coilpacks? if so how long can run it as is now?

I know that 15psi is really pushing the standard ecu, thats why im planning to drop to 10 or 12psi but i need a another actuator because the one i have doesn't run under 15psi.

Edited by Levy

How long will the current coilpacks last? Completely unpredictable I'm afraid. If the insulation has helped fix it it might be just an issue with the plastic casing, instead of the coils deteriorating themselves, which is a good sign. It might run fine for a month, it might run for 10 years or more, hopefully closer to the latter :D

How long will the current coilpacks last? Completely unpredictable I'm afraid. If the insulation has helped fix it it might be just an issue with the plastic casing, instead of the coils deteriorating themselves, which is a good sign. It might run fine for a month, it might run for 10 years or more, hopefully closer to the latter :D

Yeh hope so...thanks for your input mate :cheers:

Hi Guy`s i have Stagea S2 neo,iI have been PLAYING with coilpack`s since owning my Stagea dec 06 i have tryed few way`s & am still trying different way now have 3 set`s iam doing different,as yet i have found CRC RED URETHANE SEAL COAT which is used for motor winding,this is by far the best way i have try so far,all so look`s good,post-36964-1239969970_thumb.jpg post-36964-1239970199_thumb.jpgpost-36964-1239970677_thumb.jpg,I will post up some more as i PLAY with different way`s.cheer`s chuckie.

I had a missfire issue after 4500rpm+ with BCPR6ES .8mm. I bought BKR7E .8mm with the 'V groove' and now running perfect.

Running Splitfires too..

You do realise you change the HEAT RANGE of the plug and that was more likely to have solved your issue than the "groove".

Hi Guy`s i have Stagea S2 neo,iI have been PLAYING with coilpack`s since owning my Stagea dec 06 i have tryed few way`s & am still trying different way now have 3 set`s iam doing different,as yet i have found CRC RED URETHANE SEAL COAT which is used for motor winding,this is by far the best way i have try so far,all so look`s good,post-36964-1239969970_thumb.jpg post-36964-1239970199_thumb.jpgpost-36964-1239970677_thumb.jpg,I will post up some more as i PLAY with different way`s.cheer`s chuckie.

i like the that idea chuckie let us know how u go :thumbsup:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • My thinking is that if the O2 sensor is shot then your entire above described experience is pure placebo.
    • Here is the mess that I made. That filler there was successful in filling dents in that area. But in the middle area. I can feel dents. And I've gone ocer it multiple times with filler. And the filler is no longer there because i accidently sanded it away. I've chased my tail on this job but this is something else lol. So I'm gonna attempt filler one more time and if it doesn't work I'll just high fill primer the door and see where the issues are because guidecoat is of no use atm.
    • Ok, so I think I sort of figured out where I went wrong. So I definitely overthinked it, and I over sanded, which is probably a large part of the problem. to fix it, I ended up tapping some spots that were likely to be high, made them low, filled them in, and I tackled small sections at a time, and it feels a lot better.    I think what confused me as well is you have the bare metal, and some spots darker and some are lighter, and when I run my finger across it, it' would feel like it's a low spot, but I think it's just a transition in different texture from metal to body filler.    When your finger's sliding on the body filler, and crosses over to the bare metal, going back and forth, it feels like it's a low spot. So I kept putting filler there and sanding, but I think it was just a transition in texture, nothing to do with the low or high spot. But the panel's feels a lot better, and I'm just going to end up priming it, and then I'll block it after with guide coat.   Ended up wasting just about all of my filler on this damn door lol  
    • -10 is plenty for running to an oil cooler. When you look at oil feeds, like power steering feeds, they're much smaller, and then just a larger hose size to move volume in less pressure. No need for -12. Even on the race cars, like Duncans, and endurance cars, most of them are all running -10 and everything works perfectly fine, temps are under control, and there's no restrictions.
    • Update: O2 sensor in my downpipe turned out to be faulty when I plugged in to the Haltech software. Was getting a "open circuit" warning. Tons of carbon buildup on it, probably from when I was running rich for a while before getting it corrected. Replaced with new unit and test drove again. The shuffle still happens, albeit far less now. I am not able to replicate it as reliably and it no longer happens at the same RPM levels as before. The only time I was able to hear it was in 5th going uphill and another time in 5th where there was no noticeable incline but applying more throttle first sped it up and then cleared it. Then once in 4th when I slightly lifted the throttle going over a bump but cleared right after. My understanding is that with the O2 sensor out, the ECU relies entirely on the MAP tune and isn't able to make its small adjustments based on the sensors reading. All in all, a big improvement, though not the silver bullet. Will try validating the actuators are set up correctly, and potentially setting up shop time to tune the boost controller on closed loop rather than the open loop it is set to now. Think if it's set up on closed loop to take the O2 reading, that should deal with these last bits. Will try to update again as I go. 
×
×
  • Create New...