Skyline Owners Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
45 Posts
Discussion Starter #1 (Edited)
Firstly PLEASE CORRECT ME IF I AM WRONG IN ANY OF MY THINKING HERE ... But I am learning .... slowly ... and have come to the following conclusions by my own research ... but of course I still must always bow to the greater experience and knowledge of the many more learned people on this forum!!

So ... here goes ...

My Series 1 R33 GTS25T is missing ('popping' sound heard particularly from the exhaust ... rather than hearing anything from the engine) when I floor my right foot. This missing/popping/stuttering happens on colder evenings (like tonight) particularly. As the nights have got colder over the past 2 weeks or so I notice that the stuttering/popping is coming in at around as low as 4,500rpm now (a week back it only happened at 5300-5500rpm-ish ... but the nights were warmer then ... and I just know I am getting a stronger boost due to fresher air being induced!!). Needless to say after 6,000RPM there is no hesitating/Popping/stuttering ...

I have checked the coil packs, they are fine, the NGK Iridium sparks are gapped at 0.8mm and although a little 'cold' for the mods I have currently (at "8" heat range) they are still not so much part of the problem surely!?!!

The research I have done both by reading threads on this site and also posting threads on this site has me firmly thinking that I am overfuelling. Initially, my gut feeling was that it would have been having too weak a mixture (cos of all that extra airflow being shoved thru the engine) that was the culprit .... but everywhere I have looked in relation to Turbo-Charged Skylines with standard ECUs and Stage1-'ish' mods such as mine, which for the record, are:

HKS Panel Filter
HKS Boost Actuator (set to 0.7BAR currently)
2-Stage Boost Removed - so it spools up faster!
NGK Iridium '8' Heat Range Spark Plugs
INVIDIA/RSR 3" Cat-Back Exhaust System

.... has led me to believe that it is the OPPOSITE that is occurring and that the standard AFM or standard ECU is (due to the greater 'forced' induction of both air and proportionate fuel that is automatically 'metered in') causing the engine to overfuel from anything from 4,500-6,000rpm ....

I have learnt that I can buy and fit a piggy-back or standalone ECU that can be set to modify/moderate the amount of fuel that is being proportionately pumped in at this rev-range ... and I am looking into this. But I have 3 questions before I go ahead and spend the dosh on one:

1. Might an Full ECU reset (on my still standard ECU) help matters without having to do this
2. Are the mods I have on my R33 'severe' enough now to definitely cause an overfuel ... or is there another cause of the stuttering that I have missed??
3. How much is a piggy-back ECU either new or used and how easy is it to 'tune'

I really would appreciate any knowledgeable advice any of you may have here as it not only saves me aggro and money as well hopefully, but also it means that I can learn more and therefore won't be asking any such questions (such as I have asked in this above post!) ever again, and can also hopefully help others who come across similar problems (as my own knowledge and experience steadily increases)

Thanks

Tim
 

·
Seasoned Member
Joined
·
4,504 Posts
Have you checked for a boost leak? Are your plugs the correct grade or do you need colder ones?(someone more experienced can help you here) 2 things to think about :D
 

·
Registered
Joined
·
497 Posts
Go for the reset beforeyou buy, you can always try.
I cant see how these mods would cause overfueling. [but then again I'm also just starting]

Maybe a tip , After installed a mod, always leave the car to rev for a wile just like when you reset it, to let it learn the new conditions of the car.
Still problems go for the full reset Reset.
 

·
bla
Joined
·
17,374 Posts
i definately dont think its the overfueling... We have all had those mods on at one stage and all overfueled but never a problem like that...

In what way have you checked your coilpacks??? Just looking at the condition of them wouldnt tell you if they were breaking up (if thats how youve checked). Mine looked brand spanking new when i was missfiring. And when it went for a map the extra power just broke them up and it was playing up loads.. coilpack problem. Sir Nodrick has a missfire and as if it was blowing a spark or 2 out at the higher rev range 4500 to 5000. Loadsa pops. I lent him my splitfires and the car pulled like it should, no hesitation etc...
So im definately pointing my finger at the coilpacks.. Get some splitfires from opie oils. and As said get a colder grade of plugs.
 

·
Registered
Joined
·
45 Posts
Discussion Starter #7
your coilpacks are probably just crispy fried.
i definately dont think its the overfueling... We have all had those mods on at one stage and all overfueled but never a problem like that...

In what way have you checked your coilpacks??? Just looking at the condition of them wouldnt tell you if they were breaking up (if thats how youve checked). Mine looked brand spanking new when i was missfiring. And when it went for a map the extra power just broke them up and it was playing up loads.. coilpack problem. Sir Nodrick has a missfire and as if it was blowing a spark or 2 out at the higher rev range 4500 to 5000. Loadsa pops. I lent him my splitfires and the car pulled like it should, no hesitation etc...
So im definately pointing my finger at the coilpacks.. Get some splitfires from opie oils. and As said get a colder grade of plugs.
Thanks everyone for the help and insights here ... yeah ... it is more likely the coil packs before an overfuel as such ...

Re my sparks they are heat range '8' which I always thought was a colder plug than the '6' that they used to have ... i did not think it was necessary to get anything colder than an '8' infact there was a suggestion on another post that an '8' maybe a little too cold for what mods I have installed right now ... I have got that the right way around havent' I??? the 'colder' ones are higher performance --- that is correct isnt it? I thought that a plug that is 'cold' might take a little longer to warm up ... but can't do harm as such .. but then again I am always learning so please tell me if I am wrong about anything to do with plugs here

The coilpacks, I need to change them, and will do so before I worry about measures to correct any overfuelling suspected ...

I dont have the budget to buy splitfires as yet ... so I wondered about a few things that I would really appreciate some pointing in the right direction on:

1. Can I get away with normal replacement coilpacks (seeing as my car is not that highly modded?)
2. What can I pick up some either new or nearly new standard coil packs for ??
3. Does anyone have any for sale on this site? If not who (which traders on this site) tends usually to sell them so I can keep on the lookout?

I really appreciate all your help that you have given me as well as all others that responded to this post ...

Thanks!!!!!!!!:cheers:
 

·
bla
Joined
·
17,374 Posts
1. Can I get away with normal replacement coilpacks (seeing as my car is not that highly modded?)
Yes, but they will most likely break up again in no time..

2. What can I pick up some either new or nearly new standard coil packs for ??
New... Lol... Youd be looking at miles more than splitfires, But you may be lucky finding a good batch of used really cheap but they will most definately end up the same and you could just keep on buying duff ones. Splitfires are the only way to go mate

3. Does anyone have any for sale on this site? If not who (which traders on this site) tends usually to sell them so I can keep on the lookout?
Its very rare that coilpacks come up due to people upgrading to splitfires for the reason there causing a slight missfire.
 

·
Registered
Joined
·
45 Posts
Discussion Starter #9
New... Lol... Youd be looking at miles more than splitfires, But you may be lucky finding a good batch of used really cheap but they will most definately end up the same and you could just keep on buying duff ones. Splitfires are the only way to go mate
I figured you are 100% correct here in relation to all you have said:

1. NEW Nissan Original coilpacks are dearer and obviously not as good (for all the reasons that I read about on the web)
2. USED Nissan Original coilpacks are seemingly 9 times out of 10 a false economy and will be no better in most cases than what I have that is already 'breaking-down' on me at high boost/high revs ... (even if prices such as £50 delivered for a full set might have tempted me, but just for a few seconds, in more ways than one!)
3. Splitfires will eliminate any coil-pack issues for years to come ... period!

So ... THANKS FOR ALL YOUR ADVICE ... I thought about it and have opted for a set of 6 Brand New (Part No. DIS001) Splitfires

Thanks also for the heads-up on where to go ... Opie Oils seemed to be the cheapest at £290 inc Del & VAT !!!!

Coilpacks are a lot of money New, whichever way I looked at it ... and I just had to bite the bullet ... but at least I know that I bought at one of the best New'n'Boxed prices I have understood these to sell at ... much appreciated mate!

well here's hoping that they will end the current fiasco I have with missing at between 4,500 and 6,000 on full load when the night is colder and the boost is just that bit stronger!

Thanks :cheers:

Here's hoping that will cure the mis-fire --- it's should do
 

·
Registered
Joined
·
24 Posts
I think this is a common fault with our model as it happened to me. i started off changing the plugs, then the coil packs. this fixed it.

you may not need to change all of them, just the faulty one(s).
this is done by process of elimination, swapping one at a time till you find the culprit.

you will solve this one. good luck
 

·
bla
Joined
·
17,374 Posts
It is a pretty common fault but only due to the age of the coilpacks.

Good luck mate... Lol. had a beer last night, just reread what i said and i could of rephrased it better, lol.. :D
 

·
Registered
Joined
·
45 Posts
Discussion Starter #12
Wahayyyyy! Splitfires fitted this afternoon!!

On closer inspection, when I took the 'suspects' out to replace them ... I noticed that at least one of the 6 old standard coilpacks had a smell to it like burnt 'Bakelite' !!!

So ... once those lovely new blue Splifires were fitted ... I tried the car out at the same time as before in the evenings (i.e. approx between 10:30pm and 11:30pm at night, when the air is colder) and needless to say I couldn't 'provoke' any missing, stuttering or popping whatsoever!! The car is officially cured

Thanks to everyone for their advise here - in particular GtstTypeM, supastar, Hi5 and everyone else who helped out here!!

One thing I still am very SLIGHTLY aware of though, still, but only slightly ... (and maybe I'm just being nit-picky/paranoid) is that it still pulls a teensy-weensy bit more, er, 'willingly' ... a mere tadd I grant ... between 6,000 and 7,000 rpm....

I am wondering if that might be down to a very mild overfuel, or is it that since I have fitted the RSR-Invidia 2 Box Cat-Back Straight-Thru System ... (although I thought this was only the case for N/A cars not Turbo'd ones) that the car simply just 'breathes better' right at the top end of the rev range??

I know the car has a VVT type of valvegear system where the inlets but not the exhaust valves are VVT ... would this be the cause ...

I mean it now pulls SOLIDLY all the way from 3,000RPM thru to 6,000RPM (2-Stage Boost removed) when under full hammer ... no complaints there ... but it just seems to rev sooo strongly from 6k to 7k like I hadnt previously noticed before....

??? any ideas ...

I'm not really concerned, just a bit curious ???

Anyways, thanks in the meantime for all the support and education re the coilpacks situation ... you all helped tremendously there :)
 
1 - 13 of 13 Posts
Top