Jump to content
SAU Community
  • Welcome to SAU Community

    Welcome to SAU Community, like most online communities you must register to view or post in our community, but don't worry this is a simple free process that requires minimal information for you to signup. Be apart of SAU Community by signing in or creating an account.

    • Start new topics and reply to others
    • Subscribe to topics and forums to get email updates
    • Get your own profile page, build reputation and make new friends
    • Send personal messages to other members.
    • See fewer ads!

    Consider joining our newsletter for the latest content updates

    Click here to register


New Spark Plugs= Missfire


camoo
 Share

Recommended Posts

I have a 98 r34 gtt, 3"turbo back, FMIC, boost controller running 12psi.

while doing the 100k service, i took out its denso iridium IK20 plugs with a gap of 1.1

and replaced them with NGK bcpr6es gapped to .8

Now it misses at idle and a little when accelerating lightly up to 2000rmp, but is fine when driving normally and when hammering it.

I played around with the gapping and the smaller ther gap the worse it is, but even at 1.2, the miss at idle remains.

Its not running lean, ive checked coils, airflow meter and for any vacuum leaks, all that aside,

the miss dissapears when i put the iridiums back in....

Im stumped, my mechanic is stumped...

I know i could just run the iridiums, but there must be something causing this, and its driving me nuts....

Could it be injectors?

Any help please??

Link to comment
Share on other sites

just buy the stock plugs n gap them too .7 or.8, cheap as fu*k and will probs fix your problem n near last as long as iridium plugs- i think they are

BCPR6ES-11

Link to comment
Share on other sites

put the old plugs back in. if the miss goes away then you no it's am issue with the plugs. if the issue stays then i think you will find that the issue is with the coils. may have been a bit dodgy before hand and in the process of changing the plugs the got damaged and now they are worse.

Link to comment
Share on other sites

Sounds like my issue i have just changed my injectors..

Sounds like its on 5 cylinders if you gently rev it..

yes thats what mine sounds like, did the injectors help?

just buy the stock plugs n gap them too .7 or.8, cheap as fu*k and will probs fix your problem n near last as long as iridium plugs- i think they are

BCPR6ES-11

tried that, didnt help

put the old plugs back in. if the miss goes away then you no it's am issue with the plugs. if the issue stays then i think you will find that the issue is with the coils. may have been a bit dodgy before hand and in the process of changing the plugs the got damaged and now they are worse.

tried that, different only iridiums make it go away, also swapped my coils witha new set to test, made no difference

Maybe you dislodged some crud and it dropped into one cylinder?

blew it all out with compressor before i removed plugs, and it goes away with iridium plugs

thanks though eveyone.... :s

Link to comment
Share on other sites

Is ur ecu tunable? Some skylines do this. Its like an intermittant lean pop at idle?

If it annoys u just richen up the idle a tiny bit or keep running the iridiums if thats what ur car likes.

Link to comment
Share on other sites

Is ur ecu tunable? Some skylines do this. Its like an intermittant lean pop at idle?

If it annoys u just richen up the idle a tiny bit or keep running the iridiums if thats what ur car likes.

as far as i am aware its still the standard ecu as it has the sticker/seal on it.

im the first oz owner too, i think they have to make sure the ecu is standard when going through compliance... unfortunately lol

and yes it sounds like a lean pop, but my tuner put it on the dyno and its still rich, runs safe allthrough the rev range with a smooth power curve.

:(

im ok with running iridiums... but still i really wanna know why its doing this.. is this common at all?

Edited by camoo
Link to comment
Share on other sites

Alot of skylines have lean pop at idle intermittantly.

I normally richen the idle until the popping stops.

Why it happens with certain plugs i honestly cant answer that.

Link to comment
Share on other sites

Alot of skylines have lean pop at idle intermittantly.

I normally richen the idle until the popping stops.

Why it happens with certain plugs i honestly cant answer that.

hmmm driving through the city today i can notice it while going slow.... very annoying....

and its already running rich...

ill put iridiums back in and see how it runs...

any more ideas though?

Link to comment
Share on other sites

did you drop one of the plugs when fitting them? they are fragile things and can get damaged easily...

but yeah throw your old ones in, even if its one by one and see if the missfire at idle goes away.

Link to comment
Share on other sites

did you drop one of the plugs when fitting them? they are fragile things and can get damaged easily...

but yeah throw your old ones in, even if its one by one and see if the missfire at idle goes away.

na didnt drop any,and even then, i went and bout another set of the NGKs just to be sure.

Also tired replacing plugs 1 at a time, and untill its all iridium, it still misses....

cheers though..

Link to comment
Share on other sites

so im going to try the o2 sensor in the exhaust....

Not to sure if this will have to much of an affect but with my limited knowlede i believe this is a logical step...

Any one agree or not?

help???? lol

Link to comment
Share on other sites

NOTHING TO DO WITH THE O2 SENSOR!!!!!!

Standard Iridium plug is a (NGK) heat range 5, I believe. Try some BCPR5ES plugs, see what happens.

yeh is did nothing tring another o2 sensor, so good call...

i got some ngk iridiums to put in tomorrow, just annoying that everine else with this same angine and same mods can run standard copper plugs, yet mine wont...

Link to comment
Share on other sites

so i put in some ngk iridiums with a gap of .8

makes the miss alot better, but still dosnt completely solve the problem...

any ideas??

Link to comment
Share on other sites

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
 Share



  • Latest Posts

    • Haha likewise, take my shit box for a spin and maybe you'll end up wanting a R33 shit box again lol...  
    • @Jasoncauser looks like a tight technical track, and definitely fun! Let's hope I make it to that day 😎  
    • The springs just lets the valve bleed off pressure/oil and it bypasses the feed gallery and heads back to where the pickup feed is On the LS the oil gets the the bearings...eventually  This vid explains the OEM pump well IRT the pressure release valve and how the bypass works The oil pressure light coming on intamitantly could just be a sticky valve, but, why pull something apart and not put something better in  I believe the low oil pressure light comes on somewhere between 5-10 psi Well will stick a gauge in after the installation to see what difference it makes at hot idle and higher RPM, and by high RPM I mean 6300 RPM.....LOL
    • My bottom end was rebuilt... so I think it's standard? Or refreshed.. standard? I didn't do it - I bought it with a lot of receipts but it has new bearings, new pump and was re-assembled. Apparently I have the standard flow, standard pressure pump. I did notice the oil pressure for a LS at idle is quite low, but not critically bad, I am happy that it's at about 28psi now (that my gauges work/don't leak). I would have probably specced the high pressure one, but I'll admit my ignorance after making my other post, I don't see how the pressure spring changes things. Given the pressure is a resistance to flow... high flow should also = high pressure, and your oil pump specifications should be dictated by how the engine is built (hence the sincere thankyou video man)
    • my first time on the track, just after getting the 32. tyres were 3yr old NT01's, rotors were cactus, pads were street pads. You can see the vibrations when I hit the brakes lol. After this is when I put new BDA rotors, Hi Temp Brake fluid and Intima type 2 pads. Wow what a difference
×
×
  • Create New...