R33 Missfire - Please Help!

[Bennett]

Hey guys i have spend a lot of time searching for answers to my problem but just cant seem to find anything that works. The car used to missfire randomly a while ago then got worse and kept fouling spark plugs. So i changed to the 'wasted spark' setup. Car still missfired but it was now worse. I cleaned the AAC valve, Checked all my wiring, tried to do a diagnostic to see whats wrong but i dont have any light on my 33 ecu and the dash isnt flashing either. Some times though the missfire goes away for a bit randomly. Then it comes back again. Getting really annoying now. The other night i unplugged the O2 sensor and the car was fine for a while. The started missing again so plugged the sensor back in and it went fine again. Then started missing and now it misses whether its in or not. Today i cleaned the AFM and the car went fine for 15 mins then i tried to turn the boost from stock to 10psi and it started missfiring badly again and couldnt rev out. So i put the boost down to stock and its still running like crap. The missfire is worse under load, when i have my foot down more and when boost is higher. I also have a power fc and it does the same thing with that plugged in.

Im all out of ideas guys so i would love anyones help on this as im just so sick of it...

Thanks heaps in advance

[-Dukes-]

Check your coil packs. Classic offender

[Bennett]

Already checked them, their haltech external ones now and they are all firing. Any other ideas?

[FLY-25T]

Had the same issue, tried everything you have said and nothing worked untill I forked out for SPITFIRE coil packs,

Havent had 1 problem ever since. I think your HALTECH's could also be the problem

( Good idea to put irridium plugs in it to, stock ones from nissan arnt that expensive )

[usmair]

mate i had the same problem too... got my splitfire coilpacks in on the weekend and it works like a charm now... i used to get misfire in pretty much every gear above 5000RPM. Now its fine, smooth all the way to redline...

spend the $500 on the coilpacks... seams a lot but well worth it after the results i saw on my car.

[Bennett]

Yeah i guess it would be worth it i just dont understand how sometimes its fine and sometimes its really bad. Did you guys get that inconsistency with your rooted coilpacks?

[-Dukes-]

$500 ey, I may have to do that myself.

After getting my car serviced I got heaps of misfire at boost, I took it back to them and they charged me $270 for 1 rail of 3 genuine secondhand ones I'd only just got the car so they saw me coming,

Now after putting my FMIC in I get alot of misfire when I shift down to 2nd and floor it, so new coils are next on the list

mate i had the same problem too... got my splitfire coilpacks in on the weekend and it works like a charm now... i used to get misfire in pretty much every gear above 5000RPM. Now its fine, smooth all the way to redline...

spend the $500 on the coilpacks... seams a lot but well worth it after the results i saw on my car.

[usmair]

my misfire was pretty consistant, 2nd gear was the worst.

if i had less than half a tank it would be a little worse but if i had my foot down it wud misfire everytime

so i did some homework as around n found splitfire ones were the best

there are cheaper alternatives but didnt wanna risk spending $300 and not fixing the problem.

i got mine for $492 from nengun, took like 3 weeks so if u want them a little quicker, one of the traders on here is selling for $520 or sumthin..

[Bennett]

Yeah just wanna make sure its gonna deffinately fix the problem. I used to have faulty stock coilpacks and they felt different to this when driving. This problem just doesnt feel the same as last time. Maybe ill try find someone with coilpacks i know are working and borrow them to see if it fixes my problem then go buy some splitfires if it does.

[Kujotk]

one question lol im still only learnning and i supose ive never come across missfire in my car yet but what is misfire???? the name sugests its sort of missing a beat and probably looses power, but how do you know you have missfire?

[Bennett]

Trust me... you will know. Will feel like the cars running out of petrol. Just skips beats like you said. You get no power from that cylinder when it skips so it will be real jerky and make some weird popping sounds lol. Best way i can describe it..

[GreyGTST]

i had a misfire in my 33 and i was postive the coil packs were stuffed, it turned out that all it was was the spark plugs, they had to be regapped to 0.7, no more misfire for me.

maybe check that first, its an easy and cheap fix if thats the problem.

Edited September 2, 2008 by GreyGTST

[Bennett]

Lol i have gapped the all the way from 1.1 to .8 to .6 Nothing works... Only happens when it comes onto boost fairly hard. If i slowely accelerate with no boost then that gear WILL actually rev out. Just hates the boost. Any more ideas guys?

[Habler]

GreyGTST I guarantee one or more of your coilpacks are stuffed.

As I learnt gapping the plugs is just a band-aid solution. It creates a smaller gap for the "weak" spark created by faulty coilpacks to jump across but really doesnt get rid of the problem.

It will run fine with stock boost but when you go to add more boost (even adding intercooler etc that makes the car breathe easier could create this) the missfire will reappear. You shouldnt have to run such a low gap on your plugs.

If the car doesnt run with 1.1 (stock nissan plugs) with stock or even slightly increased boost something is wrong. And coilpacks would be the first place to start

Spend the $500 on some Spitfires and enjoy the benefits of the car running properly. I defintly learnt this over the last week.

As for Bennett I would guess that it is your coilpacks by the sound of the symptons....I know you have haltechs ones but try to find someone with a set of Spitfires and borrow them for a few hours to see if it solves the issue then buy some. The boost sounds like its literally blowing your candles out (spark plugs) lol. And yes sometimes being fine and other times not being fine is normal for faulty coil packs. Sometimes they ignite other times they dont.....

[Bennett]

Thanks mate guess ill have to borrow some coilpacks i know are working and test them. Anyone got a series 2 r33 coilpack loom for sale as mines all hacked up

[da spike]

Mate I'm in the same boat as you, i've got new irridium spark plugs (I didnt gap them as i didnt know how to and didnt want to stuff perfectly new plugs, btw did u gap urs ur self?) and still the same problem. When i hit 5000rpm it just missfires like a mother...

Could this problem be fuel related or injectors?

Edited September 5, 2008 by da spike

[usmair]

apparently the iridium ones are gapped to .8 i changed em too n nothin happened... get the coilpaks dude... makes massive difference

[arbess]

hmmm sounds like your going to have a heap of fun trying to find it, just like i did.

my thread might give you some ideas:

http://www.skylinesaustralia.com/forums/St...l&hl=arbess

best if luck.

[Bennett]

Arbess - I have read that thread alreay lol. You had some bad luck too. Funny thing happened today though, some of my wiring came loose and i found it later melted from touching the exhaust lol. Luckily it didnt go through to the copper itself like you had or i would have to fix that too.

Da spike - You gap spark plugs with a feeler guage. Little thin bits of measured metal that you slide into the spark gap and make sure its the right gap size. And yeah when you have this tool its easy to do yourself. I found my problem wasnt actually at 5000rpm but more something to do with boost or being under load. I can have my foot on the throttle a tiny bit and still rev to 6500rmp but i can also be at 2000rpm with foot flat and it missfires, infact its not even missfiring anymore, just hesitates really bad and backfires and goes absolutely no where. Although the car is fine for normal driving. So strange... The missfire could be fuel related (you may to rich/lean) but generally missfire problems in rb's are electrical. Hope that helps...

[arbess]

I found my problem wasnt actually at 5000rpm but more something to do with boost or being under load. I can have my foot on the throttle a tiny bit and still rev to 6500rmp but i can also be at 2000rpm with foot flat and it missfires, infact its not even missfiring anymore, just hesitates really bad and backfires and goes absolutely no where. Although the car is fine for normal driving. So strange... The missfire could be fuel related (you may to rich/lean) but generally missfire problems in rb's are electrical. Hope that helps...

that is exactly what was happening to mine.

i hope you end up finding it. all it takes is for a small short circuit.