Faulty Coils? Misfire At High Rpm? Read This.

[riceline]

I used Ford Dark Blue

Because I used a spare set that I have I left them under the house for 3 weeks. Once every 5 or so days I would go down and give them another coat.

Waiting to mount the intercooler before I go getting all dirty again

[benl1981]

Did you spray over even the clear side...

[mad34]

hi all,

i have r34gtt had the same popping misfire after 4000. I checked my coils because that seemed most likely. However, they were brand new the car has only done 55000km. My problem only started when i changed my plugs over from standard to iridium. so I tried gapping them to .75 that didn't work then i gapped them to .6 that seemed to fix the problem but i still get the mis every now and then most of the time it works no miss. So i guess its the plugs so for those of you that are thinking about changing plugs don't get iridium they seem to be my problem. i will get some ngk copper plugs and change them next possible chance i get i will keep you all posted and let you know if it worked.

any other suggestions advice would also be good.

[Bazelinez]

Almost 2 months are mine are still fine

Siliconed packs and .8mm gapped plugs.

[chrissso]

  chrissso said:

Hey, Have you checked your spark plug gap?

Having a look back in the thread, it seems that most problems are either cracked coils or bad spark plug gap.  If it wasn't this then it was fuel problems.... like fuel cut or blocked injectors...

It also seems aparent that only the series 1 and maybe 1.5 R33 coils have a spliting problem. With that said, all you peopleout there wih GTT's and series 2 R33's with misfire problems, might want to look at something else for your misfire issues. e.g. plug gap, etc. I put in some plugs recommended in this thread by someone - they are gapped at .8mm and are copper. Andat about $4 a plug- are alot cheaper than iridium!!! My 2 cent.

[Zahos]

  mad34 said:

hi all,

i have r34gtt had the same popping misfire after 4000.  I checked my coils because that seemed most likely. However, they were brand new the car has only done 55000km.  My problem only started when i changed my plugs over from standard to iridium.  so I  tried gapping them to .75 that didn't work then i gapped them to .6 that seemed to fix the problem but i still get the mis every now and then most of the time it works no miss. So i guess its the plugs so for those of you that are thinking about changing plugs don't get iridium they seem to be my problem. i will get some ngk copper plugs and change them next possible chance i get i will keep you all posted and let you know if it worked.

any other suggestions advice would also be good.

Cracked coils are not the only cause....

The problem lies in the standard ecu, retarding timing and over fueling when the AFM detects too much air flow (ie: when you start to run more boost).

With good coils you will experience a flat spot. With fatigued coils you will experience misfire.

Gapping your plugs down helps.

The best solution is to replace your ECU with a programmable ECU, and get yourself some new coils.

If you cant afford to do both of those, then a SAFC will also help (if not fix the problem) by leaning out your fuel mixtures.

And covering the cracks on your coils, and cleaning the contact points is a good substitute for new coils (given the internals of the coils are still good - which they almost always are).

I took the latter path...

almost 4 years ago I gapped my plugs down to 0.8mm and the misfire turned into a flat spot.

2- 3 years ago I got a SAFC fitted and tuned for a 12:1 A/F ratio and the car drove like a dream. No flat spot, no misfire, just got better and better all the way to redline.

1 year ago my misfire issues came back - so I put araldite on the coils - car was driving better than ever...

6 months ago, a missfire occured at 3 - 4 rpm - I cleaned the contact points on my coils with WD-40, and the car was, and still is driving like new....

So have a search on ALL of these points, they were coverd years ago, and I'm guessing the newer forum members dont pick them up in their searches b/c the threads are so old now, so try searching in ascending order (ie: older threads come up first)

[mad34]

hmmmmm sounds likely.

looks like i will be investing in a safc2 as mine is a tiptronic so i can't get a powerfc.

i was also thinking of going trust emanage have you heard anything about them in terms of mating them up to an auto box??

thanks for that info though its good to be able to correspond with ppl that have had the same type of problems as trusting a mechanic can sometimes be costly.

and this type of problem is hard to diagnose i know my way around a skyline engine bay, but when it comes to little problems like this misfire and you have tried everything you know of it to fix it feels like hitting a brick wall.

atleast you can go to the mechanic fully informed. knowing these sorts of things really changes the way they treat you.

[floody]

My HR31 was displaying many symptoms of cracked coils. Farted about changing coils and plugs, near to no difference. One day the ECU kick panel cover fell off - problem gone. Further investigation has shown up a sloppy ECU connector.

Just something else to look at.

[SECURITY]

guys, ive changed the tape over and over (i used the 3M pvc tape) cleaned the spring, and i still get a splutter/misfire. whats the go? after i fix the tape or clean the spring, it works for a few hrs, then comes back. someone talked about a carbon rod.. i dont have any carbon rods on or near my spring.. am i meant to?

[Rolls]

  SECUR1TY said:

guys, ive changed the tape over and over (i used the 3M pvc tape) cleaned the spring, and i still get a splutter/misfire. whats the go? after i fix the tape or clean the spring, it works for a few hrs, then comes back. someone talked about a carbon rod.. i dont have any carbon rods on or near my spring.. am i meant to?

The electrode that comes out of the end of the coil and touches the spark plug end that rod is the carbon rod.

[SECURITY]

still a bit confused... how do they replace that?

[SECURITY]

this is what happened... i took my coils out, took the rubber boot and the springs off and got my little drill set with those mini sanders out and lightly sanded away a layer off the inside of where the spring sits in the coil till it was all shiny inside... after i fitted it all back together i noticed a huge difference.. my car completely revs out and doesnt lose power at the 5000rpm mark anymore... its the fastest ive seen it ever since i bought it.

[Zahos]

thats the carbon rod that you cleaned...

you could have washed it with WD40 rather than sanding it. The WD40 will also protect it more from futher corrosion than sanding it would.

[SECURITY]

yeah, after sanding it i sprayed it with WD40 anyway

[chrissso]

Mine started spitting againg...... D'oh

So I'm pulling those colis out again for inspection.. joy.

I'll let you all know how the areldite held up.

Chris

[SECURITY]

the way i see it is electricity always finds the shortest possible route, once your coils have a build up on the inside, the usual route is no longer the best one. so you all use araldite, but you are then no longer giving it a nother way to go except down to the coil, which is fine, but its always going to be "searching" for an alternate route.

SO by cleaning the contact on the inside of the coil you are making the proper route down to the spark plug the best possible one.

im no mechanic, but ive had my fair share of electronic experience (breaking stuff) and after i sanded down the inside of the coil packs, my cars performance increased noticeably

[sl33py]

Why are ppl using araldite (any sort) when it's only rated to 60 or 80 degrees C (depending on the type u get)?

[Zahos]

The araldite i used on my coils (the cheapest one) 17 months ago before i even started this thread does not look any different, and the car hasn't misfired due to the cracks in the coils since.... it's not an issue

[madaz R33]

hi all, I have had a good read of the 7 pages of thread on this topic as my R33 is missfiring between 4000-5000 rpm, I checked the spark plugs and re gapped them down from 1.1 to 0.8 to begin with, I then pulled the coil packs out and checked them for fine carcks- none visible, also no visible grime on the copper-all clean(i think as i only did a quick check)my boost is set at 13, do u think my standard ecu is shitting its self? or there is a cracks in the coil pack? The car goes hard until 4000rpm and sorta hits a dead spot until 5000rpm and will have a missfire, the "flat spot/missfire is not all the time but mostly when laying the foot down, so go back and thouroughly check coil packs and clean the copper in them? thoughts would be appreciated, cheers Damo. p.s I am just getting ready toput a bosch 040 fuel pump and a regulator in then put my pwr fc in and have it tuned am i better off to just say f**** it and buy new coilpacks any way??

[Fixxxer]

I changed from iridiums to copper plugs soon after I got my 32 due to a massive missfiring problem. The current plugs in the car are gapped at 0.9mm and run fine up to 13psi (haven't tried more than that), and my car is running rich as all hell (in the low 10:1 area).

Here's another hint/tip, make sure your coils are getting as much voltage as possible. I'm sure my car suffers from low voltage (and is what recked my starter motor I believe). I noticed my battery connections were quite poor/dirty and corroded.

Step 1: I went out and bought a new brass negative terminal connector, cut off the old connector and cleaned the wire that connected to the new terminal.

Step 2: Also bought some 4gauge wire and two round eye connectors and made another ground wire from the negative battery terminal to the strut tower. ($11 from jaycar, only cause you have to buy in 1m lengths of 4gauge, I used about 50cm)

End result: Car is a lot more responsive down low (off boost), a lot perkier and pulls a lot better from low revs = I'm sure the car enjoys this in the high rpm range too - note to self: get grippier rear tyres.

PS: Step 3: Haven't done yet because it requires a bit of fiddling to get to the engine block ground. R32's seem to have a common ground wire which goes from the negative battery terminal to an exposed clamp that joins to the car's rails, and then continues onto the engine block. At this time mine looks extremely dirty at the rail connection and is probably why I had low voltage issues. I am intending on replacing this whole wire with another run of 4gauge wire and cleaning the rail connection and the block connection. You could also run another wire from the battery negative to the firewall.

Fixxxer