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

[gatty]

araldite/silicone up the cracks - worked on a friend 33 which was missin like a bitch

[sky hi]

i cant seem to run ova 13psi without it cutting out. do u think its the same prob or just the stock computer

[gatty]

that problem is the stock ECU ^^^

to fix it you need a "HKS Fuel Cut Defender" - it is installed onto your ECU and bypasses the 12PSI boost limit

i installed my mates - fairly easy to do, i think his was about 300 bucks from autobahn

[Lazy-Bastard]

Well I have used araldite and gasket maker on my coils and still my missing problem persists.

Next step is to swap the igniter and see if that helps :rolleyes:h

[CerealKiller]

My RB20 misfires randomly I pretty much drive like a granny (daily driver < 4,000rpm) and it occassionally misfires. Then after say 20 minutes of driving with 50% power (the misfire makes my car sound like a boxer engine) it's all good again. Do you guys reckon the araldite / electrical tape trick will sort my issues out? I've had UAS and Grey Imports both check my coils with nothing bad found...

[nothing]

wow this sums up my problem perfectly. I got a turbosmart bleed valve and a trust v-spl FMIC fitted and now can't go over 5000 rpm without it misfiring (feels like boost cut but turbosmart is as low as it can go)

took car to dyno and they said my coils are farked and they are going to put on some aftermarket ones. wish I had read this thread 24 hours ago (new coils were installed today and is being put back on dyno in morning)

could of saved myself 800 bucks

[benm]

Considering my Splitfire coils cost me only $615 fitted.

[nothing]

$650 for coils and labour

$150 for dyno time

[benm]

Oh, I misread your post.

How could you have saved $800? By aralditing your coils?

[ECR033]

My RB20 misfires randomly I pretty much drive like a granny (daily driver < 4,000rpm) and it occassionally misfires. Then after say 20 minutes of driving with 50% power (the misfire makes my car sound like a boxer engine) it's all good again.

My car's recently developed the exactly same problem over the last week or so and I can't understand why the misfire is only intermittant and doesn't happen all the time. I had the car at the tuner today and it misfired briefly while we took it for a road test, but no matter how hard we tried to replicate the same driving scenario, the thing didn't misfire again. Took it out for a drive tonight and what do you know, the bugger starts misfiring again for a brief period.

Without looking at the coils yet I'm not convinced that they are the problem due to the intermittant nature of the misfire, as one would think the misfire would be permanently there if a coil was faulty. Tuner thinks it could be a faulty crank angle sensor, but even he seemed a little confused as to why the misfire was only happening intermittantly. Could this be a possible solution? If so, how much would a replacement crank angle sensor cost?

Thanks guys.

[siksII]

its probably the coils

this is how u can tell which ones are stuffed, drive it around till its hot, stop the car somewhere dark, (with the coil cover off) and you can actually see the coils arcing like little flashes of light around the base of the coil.

give it some revs if its not doing it, but mine was doing it enough to see which coils were faulty even at idle,

coils 1 and 6 are stuffed on mine, i cant rev past 5500 or use more than half throttle, it happened suddenly last week, i guess a hot day and hard driving did it.

i will araldite them soon and see how it goes.

[jared parker]

hey i have the same problem ,went to willowbank and raced a few other 33s around the track tey wiped the floor with me and mine was the only one that missed from about 4g on we thought it may have been vacume troubles but could not find anything ... so elec tape here i come

[Neosaber]

i did my coils with araldite and it worked awesome, any1 considering it JUST DO IT....only thing now is at around 12psi when i have smash it the engine shudders and cuts the fuel i'd say...coz it goes knowhere....pooey....stock ecu prob???

[frog_stompR31]

i have a rb20 in a r31 and it misses on no6 at idle ive done every thing and it wont go away i look at this thred and then looked at my coil packs none are cracked but i can seem to find what it is does anyone know where i can get the hand held plug in diagnostic unit .... and how much

or know what my prob is i have also replaced all plugs and igniter injector no6 and injector o rings also replaced no 6 coil

[Cubes]

Troy,

Blackwood Auto & Dyno have a diag unit that will plug in and tell you what you want to know.

I don't think it will be able to tell you what you want to know though.

They charge $35 for a few power runs, for me it included plugging in the consult.

[Wild33]

PROBLEMO SOLVED- thanks to this thread. I had a nagging misfire for the past three years and it seemed to get worse when i bolted on a turbo back 3 inch zorst and increased the boost. It used to muliple misfire at 4500-5500 at .7bar... but now sweet to .8!!

I fixed it like this:

got one of those school plastic folders with the clear pages in the middle-you know the ones you get for a buck. Well I cut up the black outer plastic covers (approx 50mm by 30mm) and inserted them in between the plastic housing of the coil and the square metal outer ring. I cut it so that it couldn't slip out by cutting a slight angle. I glued these in with silicon. I did this on both sides of the coils. On some coils the plastic cover was too thick, so i used a skinner plastic from another brand of folder.I had the hairline crack as in the photos shown on this pagei just smeared this with aradyte.

Some of the gaps had gunk-maybe carbon or crap sandwiched in the gap... so i got some 100 tough sandpaper and slid it through and cleared out the gunk and roughened up the plastic for better adhesion.

After that, being paranoid, I wrapped the whole unit skilfully with 3M pvc tape. Went for a ride, and sweet..no misfire!!!

The only thing I am going to change is the pvc tape- i will try to get some self amalgamating tape that good for high temp.

Definitely this bodgy but effective method is worth doing...but i hope it will last .. and i think it should.

[siksII]

i araldited my coils on the weekend and it did not help, coils 1, 3 and 6 are still arcing to the metal frame surrounding them...

[Wild33]

i araldited my coils on the weekend and it did not help, coils 1, 3 and 6 are still arcing to the metal frame surrounding them...

YOU NEED TO INSULATE THE METAL FRAME AND THE PLASTIC COIL PACK BY SQUISHING HITEMP SILICON IN THE GAPS (VERY TRICKY BECAUSE THE GAP IS SO SMALL) OR INSERTING A THIN PLASTIC CUT OUT RECTANGLE, ON BOTH SIDES OF THE PACK WITH SILICON SMEARED ON THE SIDE THATS AGAINST THE COIL PLASTIC.

[Wild33]

i araldited my coils on the weekend and it did not help, coils 1, 3 and 6 are still arcing to the metal frame surrounding them...

YOU NEED TO INSULATE THE METAL FRAME AND THE PLASTIC COIL PACK BY SQUISHING HITEMP SILICON IN THE GAPS (VERY TRICKY BECAUSE THE GAP IS SO SMALL) OR INSERTING A THIN PLASTIC CUT OUT RECTANGLE, ON BOTH SIDES OF THE PACK WITH SILICON SMEARED ON THE SIDE THATS AGAINST THE COIL PLASTIC.

[siksII]

YOU NEED TO INSULATE THE METAL FRAME AND THE PLASTIC COIL PACK BY SQUISHING HITEMP SILICON IN THE GAPS (VERY TRICKY BECAUSE THE GAP IS SO SMALL) OR INSERTING A THIN PLASTIC CUT OUT RECTANGLE, ON BOTH SIDES OF THE PACK WITH SILICON SMEARED ON THE SIDE THATS AGAINST THE COIL PLASTIC.

Hey mate, relax with the CAPS

i taped plastic pieces between the coils and the frame as a last resort, this lessened the misfiring, but as the car got hotter it was pretty much the same as before, and oh yeah, the plastic started melting

that was my last resort, so yesterday i just ordered a set of spitfires. ($$)