How To Fix Missfire Problem

[MKDR33]

Problem:

My S1.5 R33 used to missfire from around 4500rpm til about 5500rpm @ 12psi+ (especially in the cold). I tried everything, from installing an SAFC II piggyback to tune the AFR to regapping my spark plugs etc.

Solution:

The stock coil packs have a hairline split on the side of them, which at high boost levels, the spark tends to not follow through to the spark plug, but jumps out of the coil pack. After sealing up all my coil packs, my car runs much smoother now, I can boost it to 16psi and I dont get any missfiring.

D.I.Y. Fix:

For a quick and cheap fix for this problem.. (the following was done with spark plugs regapped to 0.8)

R33 GTS-t Fix (Im guessing that the same problem occurs on the R32 & 34):

1. Take off the plastic cover in the middle of the engine (between the tapper covers) which covers your coil packs

2. Unplug and unscrew each coil pack (all six) and take them out

3. Holding the coil packs vertically, inspect the sides and locate the hairline split (as shown below)

4. Once you locate the split, using GOOD electrical tape (cheap stuff WONT work), tape over the split a couple of times, making sure the tape sits flat over the split and seals it firmly (as shown below)

5. Once you have taped up all 6 coil packs, screw them back in place and reconnect the plugs

6. Place your plastic cover back over the coil packs (I have left mine off for better cooling of the coil packs)

Done!

MORE HELP:

For more info on taking out the coil packs ---> http://www.skylinesaustralia.com/forums/in...showtopic=42819

Another alternative is buying Splitfires, but this is around $700+ dearer to do..

PS. Make sure you use GOOD electrical tape, as cheap stuff tends to get hard and peel off from the heat.

EDIT: Or as QRI05E recommended - for a more reliable seal, use 'Shelleys Industrial Silicon Sealer 401' for only $11 @ Bunnings.

Edited September 27, 2006 by MKDR33

[pplo]

Hey mate,

Do you tape them around or up and down..

see pic..

thanks!

would be sweet if you could show us close up pic with tape on

Edited May 25, 2006 by pplo

[pplo]

hey mkdr33,,

what turbo are you using to boost to 16psi now??

not the standard is it??

thanks!

[MKDR33]

HKS 2530kai

Edited July 28, 2006 by MKDR33

[QRI05E]

The tape will eventually soften and shrink due to heat... a much more permanent method would be to use Shelley's industrial grade silicon which is heat proof till 205 deg/C... $11 at Bunnings and has got rid of all of the misfire…

Cheers

[MKDR33]

ive had mine like this for about 4 months now, i still havnt had any problems.. but it sounds more reliable to use shelleys ind. silicon..

thanks for ur post QRI05E

[QRI05E]

No problems buddy... glad to help!

Cheers

[WogsRus]

these must be series 2 coils series ones are different, atleast they are on my mates seddan. the coil goes all the way arround, so the only way to fix any cracs is to epoxy the entire thing, as we did.

simply dipped the whole thing in 2min epoxy, worked well.

[MKDR33]

mine is early 95 R33 i think its S1 though, S2 came out early 96 i think..

[Whiplash]

I've got a S1 aswell sounds like i'm having the same problem as you

[MKDR33]

this problem usually arises in winter.. id say its the coil packs Whiplash..

[QRI05E]

Epoxy glue is excellent for bonding materials however loses strength above 65 deg/c and considering that silicon is a MUCH better insulator and the Shelley's ind. silicon can withstand 205 deg/c makes it a much better choice...

[Staunch]

excellent work fellas, got the exact same problem described here. gonna give this method a whirl and see how it goes.

[MKDR33]

i went to bunnings today and bought Shelleys Industrial Grade Silicon Sealer 401.. Removed the electrical tape from the coil packs and resealed with some silicon.. waited around 4 hours so it dries up nicely n took the beast for a thrashing..

i must say, it does seem more reliable to use the silicon.. when i took my coil packs out today, i did notice the tape had shrunk a bit a little bit over the split..

[QRI05E]

Good to hear mick! $11 for silicon beats $900 for coil packs

[MKDR33]

indeed

[Guest Rotary20B]

Hi,

I just pulled my coils out, plugs will have to wait till I find a proper plug socket for it

Anyway, I couldn't see any noticeable cracks, only what looks like casting marks

My S1 coils are different to the ones pictured above too

Should I just seal them up anyways? Or wait till I get the plugs and a socket tomorrow and just try re gapping the plugs?

The coils have a bit of oil covering them too, don't think tape would stick too well, whats the safest thing to use to clean them up?

Also, has anyone tried self amalgamating tape?

This is, mine only stuffed up after I upgraded the exhaust

So I thinking it is just the plugs need regapping

Edited August 16, 2006 by Rotary20B

[WogsRus]

had a simmilar problem, so i took out my coils and allthough they all had thesam resistance and no cracks visible, i wrapped them up for good luck, i took out the plugs to discover it had two different types, no wonder it had a missfire.

So i changed the plugs to BRK6AYE or something like that, gapped to .8 mm and all good, pulls way harder and no missfire so far.

YEEEHHHA, bring on the boost

[GTR_Legend]

Mine did not have any cracks, pulled them out twice and checked them, one thing you cant visually check is wear. Waiting for my new splitfires to come from Japan, cost $540

[Kennedy]

Mine did not have any cracks, pulled them out twice and checked them, one thing you cant visually check is wear. Waiting for my new splitfires to come from Japan, cost $540

I couldnt spot the cracks on mine either but I taped them up anyway. Problem solved. Off to bunnings to guy some silicon