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Missfire Question?

Levy

By Levy,
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Levy Collaborator

Levy

Posted
Posted

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

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https://www.sau.com.au/forums/topic/355444-missfire-question/
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BOOZTJUNKEY Proficient

BOOZTJUNKEY

Posted
Posted

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

Levy Collaborator

Levy

Posted
  • Author
Posted

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.

t_revz Grand Master

t_revz

Posted
Posted (edited)

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
Levy Collaborator

Levy

Posted
  • Author
Posted

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:

Levy Collaborator

Levy

Posted
  • Author
Posted

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

t_revz Grand Master

t_revz

Posted
Posted

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
Levy Collaborator

Levy

Posted
  • Author
Posted

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...
Galois Veteran

Galois

Posted
Posted (edited)

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
Levy Collaborator

Levy

Posted
  • Author
Posted (edited)

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
Galois Veteran

Galois

Posted
Posted

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

Levy Collaborator

Levy

Posted
  • Author
Posted

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:

chuckie Mentor

chuckie

Posted
Posted

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.

bubba Grand Master

bubba

Posted
Posted

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".

Levy Collaborator

Levy

Posted
  • Author
Posted

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:

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