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Missfire Boost@4500-5500 RPM - The Answer! (for me at least!)


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Hi i have a r34 and for some reason it goes into somthing like a limp mode where its only firing on 3 or 4 cylinders , Ive just replaced oxy sensor and plugs and 2 coil pack have been repalced ive cleaned the air flow meter aswell . Could it still be the coil packs ? I so run out of ideas . Because Its happening twice a day on the way to work and then on the way home. I used to be able to restart the car 4 times and it would be ok but now that doesnt help. The only other thing that happens is my slip light comes on and trac control light and the engine light and abs aswell. I went to the auto elec and he pluged his computer in and came up with a error 21 ? dont know what that means . Can somone please help.

I also have an R34 GTT with similar or same problem.

My car has full 3inch exhaust and dump pipe, apexi power fc, K&N air filter and is run at standard boost. Note: The extras have just amplified the problem.

1. For some reason, in approximately the first 30 minutes of driving I will get random misfiring? (engine sounding like a WRX). Sometimes it starts like it, then goes and some times it just cuts in whilst driving. It is usually worse during winter and cool weather. Considering most of my trips are less than 30 minutes, it happens a lot and is quite annoying.

When this happens, the smell of fuel (sulfur smell) is stronger.

2. Also when up around the 4500 - 5000rpm mark the car (when warm) just seems to give out, sort of misfiring.

To answer part of your question. I had the same problem "slip light comes on and trac control light and the engine light and abs aswell". Oh and the actual traction control wouldn't work whilst these lights were up. I think I may have caused this problem by travelling too fast around a bumpy corner whilst the traction control was on (but not 100% sure). I noticed that when all of the mentioned lights came on, the car would splutter slightly. The problem of the dash lights coming up was taken away when power fc installed. I think also a good auto electrician may be able to fix the computer error.

Looking at the manual which I purchased after the incident, states that you shouldn't spin the wheels with the traction control on whilst going around a corner.

I am still not sure if my current problem is actually the same problem (without the dash lights coming on), just enhanced by the addons. Although now when the car is misfiring, the traction control still operates correctly.

I have had mechanics check out the coils + tuned etc, they had the car for quite some time and they couldn't seem to find the problem. They said the coils looked fine.

I am not really mechanically minded. I only really know what I have been shown which isn't much.

I have read through all the old posts and wondered if taping the coils etc will correct my car problems or should I find second opinion mechanic and have re-tuned etc.

I love all skylines and can't stand the thought that my car is running shite.

Any help would be greatly appreciated.

  • 2 months later...
<br />I *HAD* a miss in my R33 GTST when the air was cold out side or I put the boost up high. This happened at around 5000 RPM, after many months of chainging plugs, coils etc, I finally know what is wrong and a fix (not sure how long the fix lasts!)... <br /> <br />(the reason it does it more when the air is cold is the Boost was higher due to more dense air) <br /> <br />Note: All Coils tested FINE with a multi meter - This is not a valid test for this problem! <br /> <br />after a really really good examination of the coils it seems that there were lots of scorch marks and some other really small marks, which looked like the spark was jumping from the case of the coil!!! Looking VERY closely, I found that all bar 1 of my coils have a hairline (almost invisible) crack on the front of the coil! (I will post a decent picture later): <br /> <br /> <br />
          ~~~<br />
<br />
         --|  <--- Ignition Plug<br />
<br />
  ~~~~~~~~~~<br />
<br />
 ~~~~~~~~~~~~<br />
<br />
 ~~~~~~~~~~~~ <br />
<br />
  ~~~~~~~~~~ <--- Crack Here! Top to Bottom and on Some, Into Plug Tube<br />
<br />
  ~~~~~~~~~~<br />
<br />
         ~~<br />
<br />
         ~~ <--- Spark Plug Connection<br />
<br />
         ~~

<br />(Sorry about my Crappy ASCII Picture!) <br /> <br />What I did was tape the lower half of the coil. <br />

          ~~~<br />
<br />
         --|  <--- Ignition Plug<br />
<br />
  ~~~~~~~~~~<br />
<br />
 ~~~~~~~~~~~~<br />
<br />
 ~~~~~~~~~~~~ <br />
<br />
  ~~~~~~~~~~ <--- Tape here<br />
<br />
  ~~~~~~~~~~<br />
<br />
         ~~<br />
<br />
         ~~ <--- All the way to here<br />
<br />
         ~~

<br />I no-longer have a miss!!... I put the boost up even more then before, and still no miss!! - this morning was nice and cool outside on the way to work - still no miss!!! <br /> <br />Anyone having problems with missing, just tape the coils you already have, use a REALLY good Stretchy Electrical tape... not the 25c crap you can buy (this was useless!) - I will have to try and find some high temp non-conductive glue and try it some time too!<br />

<br /><br /><br />

I have that exact same problem,,plus a few more, but lets get this out of the way.. i wanna try it but can you show me a pic of how you did it?

hey my r33 s2 (turbo back exhaust, cai and pod, boost controller on 10psi) suffered the same problem and at 4500-5500 sounded like a machine gun going off.

i pulled out all the coils tested them first with a multimeter and then inspected them for cracks, they looked fine but to be safe i coated them in a high temp electrical sealant (15 bucks from bunnings) and thought all my problems would be solved.

Car was no better at all and still had the horrible miss. i then pulled the plugs out and gapped them to .8mm and resest the ecu and gave it a good thrash while it was re-learning.

Problem solved! my car revs harder and faster to redline without missing a single beat. Very very Happy :blush:

just thought id share my experience with everyone, good luck to all with this problem.

  • 2 weeks later...

as i posted in the other thread like this going around...i started to get a missfire 2 nights ago out of no where!

usual first stage mods that ive had for nearly 1 year no probelems at all, so i suprised how it just started to missfire

anywayz i went to repco, bought a tube of Loctite silicon/gasket maker HI TEMP (rated for 350degrees), pulled my coils and saw noticible splits in almost all...gave them a good coating on every side, underneath and on top, left to dry chucked them bak in

took for a quick squirt and the problem has 100% disappeared, and its running 11.5psi stock ecu, no miss, no flat spot no nufin....GOOD AS GOLD

but as others hav said, this is only a temporary fix until i hav spare $$ to put in splitfires

:/

ok well took it for a good drive and after about 30mins of driving, it still misses between 4500 - 5500 rpm

it has iridium plugs in it, but are around 60,000kms old, so im thinking of changin the plugs and go from there...

  • 3 weeks later...
  • 3 weeks later...

Probelm: Misss firing at around 4000rpm +

changed plugs (8mm gap) running 13psi,

still missing, bought new superspark coils $499, fitted them, started it up, & JACKPOT!!!(i knew i installed it correctly, lol) then took it for a drive & as soon as i drove off, i felt it was more responsive, drove like a dream.

Mods include: Cooler, stock exhuast, 3" exhuast 13psi

Problem solved by new coil packs :)

:D I just bought my Skyline r33 gtst series 1 from the dealership. Car has boost controller gauges etc and a bit of work done 3 inch from turbo back etc. When it hits 4500-5500 rpm it starts to backfire like a machine gun. Only happens when i lead foot it. Happens no matter what speed I am doing. If i'm light on the foot it's ok but is driving my insane. I put new spark plugs (95 dollars) and yet to tape the coils. What tape should I use? And where should I buy it from? If this fixes the problem (Tape) thinking of getting the splitfire coils off ebay. That suggested? Cheers

EDIT** How long does the tape last for? ALSO does anyone live in Berwick that i can use thier coils so I can diagnose to see if it's my coils? I don't want to blow 600 bucks on coils i don't need. I will provide 6 pack of whatever beverage you like :)

0425630702

Edited by r33gtstzilla
  • 3 weeks later...

Taped up the coils. Taping them up doesn't last long... Got really good tape and taped them up like no tomorrow... The heat lifts up the tape but now i know it's the coils!! When i get my sound system sorted going to get some splitfire coil packs off the net for 610 inc post. The taping has made them better and I have taken off the cover to let them cool quite a lot more. Does ping and pop, lets just hope my turbo doesn't go soon beacuse it doesn't sound healthy!! :D

Oh yeah another interesting point i found out shortly after doing this was a mechanic told me some Nissan manuals actually say to coat entire coil packs, rubber boots included, with silicon spray, on service intervals. very interesting! The mechanic went on to say that once he has put everything back together (except the plastic cover) he lightly coats the whloe valley between the tappet covers in the sylicon spray!

Also for the record i gapped my plugs to .75. Reason for this was purely because i noticed a lot of the r33 S2 and r34 owners have reported needing slightly tighter gaps than previous models. also i am running platinums, and the general concencess seems to be that they require more of the coil packs energy than coppers. Instead of wasting money on new coppers i thought for now i'll just gap it a little tighter to take the pressure of the pcaks.

Hope this helps.......

Well I recently purchased NGK Iridiums (gapped at 1.1) and Yellow Jackets...so we're at opposite ends of the spectrum Danny! Going to install tonight so it will be interesting to see the effects. Might have to re-gap them to 0.8 if I get any troubles.

Edited by Birds

why does it fix everyones problems but mine :)

im running all bolt ons, hi-flo turbo at 15psi, injectors, AFM, fuel pump

apex power fc and car has only done 36,000kms (genuine actually)

but my problem is that it only "missfires" at about 5000-6000rpm once and

only in 3rd or 4th (havent got there in fifth) :)

not in first or second.

put in new plugs gapped to .8, bit better then to .75 with no change

i bought the selleys industrial grade silicon covered the whole coilpacks

and clean the inside but it still does it :(

i think im gonna be up for splitfires ay??????

and another tuneeeeeeee

any help much appreciated

Hey mate the problem sounds different becuase it should happen in any gear and more than once. its not a precise thing its pretty random! you should be looking into some other possibilities! your packs shouldn't be that bad at those sort of km's either!

I could be wrong but it sounds different!

Good luck mate there's nothing worse than a prob ya cant work out!

  • 3 weeks later...

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