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

[cme33]

my prob only came when i tried to turn the boost up, i freaked out thinking it was something else i took the bleed valve out and the problems have never gone. i tried the tape trick and it lasted for about 6 months. It ran like a dream, i even refitted the bleed valve and turned the boost up (12psi) but in the last few months it came back.

It does it worse when i have a full car with people or going up hills under heavy load (right foot to the metal) even by myself. I've tried re-taping them but it's no use.

I have been able to see very fine... hair line cracks on a few coils and you can notice also by the dark/grey marks aound them where the spark's been eartheing out. I've once again removed the bleed valve and back to standard boost i seems to go ok, still does it every once in a while...

It's a coil problem and will need to solve it with new ones (splitfire) but be aware that series 1 are different to 2 and it's my bad luck that series 2 are harder to find!

Anyone know how much for a set for series 2?

[O.I.C Napster]

I had this problem for about 2 weeks and i checked my coils tonight and found one hairline crack, did all the glue and tape thing... And SWEET more boost re gapped the plugs to .8 and yeah sweet as. Thought i would let everyone know too.

NICE FIND

Matt

[Link]

Found my problem coil - number 5!

Taping them up this weekend and ill see how they go

[drewr33]

Not sure if this has be covered.

My r33 is missing but only at cold nights (more power) would installing a PFC fix the miss?

OR

are r33 gtr coils interchangable in a r33 s1.5?

Thanks

[Link]

Finally fixed my issues!!

Replaced my coils with another stock set and put some regapped iridiums in and she runs perfect!

Had it dynoed before and after to see if it was afr and i was down 20kw!!!

I think it fixed my hunting issue as well, car revs nice and smooth through the rev range - its like a new car

[drewr33]

OK i got a question.

Will fitting a PFC make the miss fire problem better or worse?

[Kennedy]

OK i got a question.

Will fitting a PFC make the miss fire problem better or worse?

Same

[Kennedy]

My stuttering just came back 6 months after my silicon job. Pulled the coild out and found a 2mm washer sitting under coil 3. WOOPS. Put it back together and all is fine now. Silicon is the shit.

(BTW Also checked my coil path to see if there was any gunk surrounding the spring but there was none...not as single speck. Shiny and silvery)

[drewr33]

OK i got a question.

Will fitting a PFC make the miss fire problem better or worse?

Ok guys.

Got my car tuned yesterday with the Power FC.

Before with the standard computer I was having bad miss problems.. (known as cracks in the coil packs)

I fixed it for a while but then came back.

Anyway. Got car tuned and is running sweet. No misses.. and still the same coil packs.

I had a chat to the tuner about them. He was saying alot of ppl think its the coil packs, but really its a mixture of the standard computer + standard coil packs + non genuine spark plugs.

So anyway I was glad I didnt buy Splitfire's and for anyone who is worried about there coils a new computer should sort out the problem.

Cheers.

[a20089]

Well I've got spitfires and just recently my car's been displaying these symptions. (Parts unknown age but certainly less than 4 years old)

Na, was just shitty wollies 95oct fuel that took ages to filter through. Back to the good stuff.

Edited January 29, 2007 by a20089

[heller44]

I checked last night, in the dark, 1 2 5 & 6 are arcing. Nice blue flicker as well.

Pulled the coils and checked and there's not a lot to see. Will give them a coating this weekend and then try again.

One thing I was unsure of, When I pulled the coils to check, there was no cap on the spring touching the spark plug. It went coil --> spring (inside rubber bootie) --> spark plug. Am I missing bits or is this how it is meant to be? Unsure..

Thanks..

[VLT025]

are you guys taping the round part of the coil? anyone tried Heat-shrink? That would seem to be a good option thats easy to remove should you want to later....

[Hardman69]

My R33 GTS-T has always had weak spark: When I did the Intercooler, full exhaust & standard ECU, it broke-down the spark when the factory boost solenoid opened @5,500rpm. Installing the PowerFC brought the mixtures back into sensible land, and all was good for quite a long time (Std. Turbo ran out of exhaust flow @180rwkw).

With a more serious turbo installed, I wicked up the boost a bit - and ran out of A.F.M. signal @9psi & 6600rpm.

D'oh !

Any more boost was blowing out the spark again too.

So I did the Silicone trick, and . . . . . . . . 18psi @5,000rpm and feelin' FINE ! ! ! !

Now I just need one of those fancy Z32 AFM's ! !

[mjai]

Well i had the above symtoms, regapped my sparkies to 0.8 and tapped the coils.

Sorted.

[Rolls]

Well misfire is completely gone after remap, turns out it was getting down to ~9:1 afrs hence the rich misfire on cold days. I suggest this to anyone else still experiencing it, get it on the dyno and see how rich its getting.

[Rednisr31]

tried this, no luck BUT i can get my car past the backfire and it tries to hook all the way down, abit rough tho but it would get there just in no hurry at all

any ideas? maybe igniter?

free revs fine tho

but boost sounds funny and the bov makes weird noises when you change gears, more high pitched

Edited March 23, 2007 by Rednisr31

[RipNGrip]

Hey guys,

This topic is increbily helpful but is the bain of my skylines existence at the moment. In short my car was misfiring and heistating and there were hairline cracks which were on several coilpacks on remove i smashed the ignitor loom. I got a replacement loom which was a rb26 loom (wrecker at STZ automotive was an idiot) and a Splitfire coilpacks..... rb26 loom + SP coilpack = misfire at idle. So i changed plugs NGK irdiums - regapped (.6 to 1.1) , fuel filter, quick check for intercooler splits, quick check on vaccum lines, cleaned AAC valve, cleaned and resolder AFM, swapped ignitor with a mate, new walbro fuel pump, SP coilpacks and got AN RB20 loom and now..................................

slight misfire on idle leading to random stalls with the "battery light comes on"

?failing O2 sensor

?failing alternator - battery is quite new

Edited April 16, 2007 by RipNGrip

[Project mu]

As well as coil packs it is also worth checking you boost duty settings and your dwell v rpm settings if you have had your car tuned. ie you have a power FC. I found that both my settings were too high. If the power FC detects boost more than 0.2bar above the boost setting it will apply a fuel/power cut.

You need a datalogit to check all this stuff, justb letting you know it isn't always as simple as the coil packs. My car is now 100% after hesitating at 4-5k rpm. I did replace std coil packs with Splitfires but the problem persisted.

Good Luck

[PSI086]

Very good read. I've been trying to find a very similar problem on a 94 WRX which has a similar coil on plug set up. Heatshrink would work as well as if not better than tape and silicon wouldn't it?

[clkngezz]

hey guys i just got my new exhaust system on today, and my car has been missing since! why would it do it after i get the exhaust on? i have a 3inch split stainless dump, gutted cat, to 3inch stainless kakimoto exhaust. any ideas, i have just had my 100k service, it only misses when it hits 2nd stage boost at 7psi, after 4 1/2 rpm ?? ideas would be awsome