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Discussion Starter #1
Hey guys,


Getting lots of misfiring on my R32 GTR. Car ran too rich and plugs fouled up (using NGK iridium, 8 range, gapped at .8mm). Anyways, got the car running, for about 15 min it was running on 4-5 cylinders, finally cleared up and is running on all 6. Around 6000-7000 (in neutral) i'm getting backfiring/misfire. Also, throughout the revrange, anytime I get into boost i'm getting these misfires. I can go partial throttle (maybe 35-40%) and get into boost to around 10psi, but thats it.

Also, sometimes it misfires then the ignition cuts out for a second (rpm's start falling even tho I have my foot on the gas), then if i let off and give gas again it starts to accelerate until I misfire again.


The plugs when I took them out where completely black (not wet though). Should I be getting a new set of plugs? The iridiums seem to be fouling up a lot, should I go for some platinum's? Possibly coils or the ignitor?

Any help would be greatly appreciated. Also, the car is running an Fcon V Pro (only 1 tuner within my coast, and they have no time right now to tune or look at it).

Thanks :D
 

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Misfire

Try connection plug to ignitor first, with all plugs fouling I don't think its coilpacks. I have known ignitors to fail giving these symptoms before complete failure, also check earth lead to ignitor.
 

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Get a new set of plugs first. 0.8 gap again ngk i use.
Then try it. give her a bit of a journey.

****
 

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Discussion Starter #4
m6beg said:
Get a new set of plugs first. 0.8 gap again ngk i use.
Then try it. give her a bit of a journey.

****

Ordered up a new set today, hopefully they arrive soon (its still 4pm here). On the old plugs I drove around for 20 min or so and it was the same thing.
 

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Discussion Starter #5
Budzey said:
Try connection plug to ignitor first, with all plugs fouling I don't think its coilpacks. I have known ignitors to fail giving these symptoms before complete failure, also check earth lead to ignitor.

Will check the ignitor, for some reason when I purchased my car there was a spare one in the trunk, so i'll try swapping it as well. What might the earth lead be? (possibly the ground??)
 

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check vacuum pipes had that before, would idle ok but then when reved or driven on boost would jump around. also take off afm's and spray with brake cleaner then dry and refit, one of mine was choked with oil cant see that allowing it to give acurate readings lol.
 

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Discussion Starter #7 (Edited)
Here's an update for you.

Changed plugs to brand new NGK BKR8EIX gapped to .8mm, checked the ignitor wiring (looked okay etc.), and for vacuum leaks (vacuum reads same as before the problem). Absolutely NO DIFFERENCE :mad:

Basically this is how its running, very random. Getting lots of bucking at low rpm's and when trying to get into boost. Occasionally I can go about 40% throttle in 2nd and the car boosts to 14psi and is fast as usually. If I try to go more than that the ignition cuts or I get misfire/backfire.

This is what I *think* is happening. The coils are messed and aren't allowing enough spark for the fuel, car is running super rich so the plugs foul and the f-con cuts the ignition to stop the car from running way too rich. Also, the F-con doesn't detect misfires so it keeps on fueling as normal. The new plugs after driving around for 10 min were completely black!

What do you guys think? A friend also suggested it might be the CAS?
 

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I were getting crazy misfire 5000rpm upward as if the car hit a wall. splitfire coilpacks and new plugs sorted it and the splitfires are pretty much best you can get altho not cheap. Gapping from 1.1 to 0.8mm did nothing for my plugs before I had the coilpacks fitted :/

crank angle sensor would be fiddling about with the ignition timing giving slightly erratic idling wouldn't it? dont know much about that one tho I'm afraid :(
 

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I had exactly the same on my car over the weekend. It was on new plugs and packs.
Did some reading on here for a good few hours, and someone had suggested re earthing the Ignition Amplifer.
Worth a try as its only earthed by a tiny bit of wire, and its now as soomth as babies bum :)

5 mins fix!!
 

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Discussion Starter #11
Well I brought the car into work and tested the resistance of the coils. Results seem odd though. ALL of them tested to either 1.1 or 1.2. I wouldn't think that all of them are shot at the same time. Does this seem weird to anyone else? It also seems odd that they would all decide to go at the same time.

Any other suggestions? Going to also reground the ignition amp tonight.
 

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Discussion Starter #12
Well I swapped another ignitor and there was no change. Took a couple of small vids so you guys can see what I'm talking about when the ignition cuts out. When you see the revs just stop for a minute, its not me letting off the gas, its the ignition cutting out. Sorry for the crap quality, its from my phone.

The videos are actually in .mp4 format, my stupid server won't accept files with any mp extension on it. I've put .avi at the end, so right click and save as, then change the ending to .mp4 You'll need a newer quicktime player to view.


Driving, some misfire, tiny bit of partial boost
http://autodome.ca/highline/r32 gtr/misfire.avi

Misfire
http://autodome.ca/highline/r32 gtr/misfire2.avi

Partial boost in 2nd gear (about 30-40% throttle)
http://autodome.ca/highline/r32 gtr/misfire3.avi
 

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When mine did that it was the CAS sending all sorts of weird timing signals out. Sounds identical to your symptoms. A new one from Abbey sorted me, but i needed to have the car plugged into a Consult to diagnose it. Had tried coils/ignitor/plugs to no avail. I dont know how you can test the CAS, sorry.
 

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Discussion Starter #14
When mine did that it was the CAS sending all sorts of weird timing signals out. Sounds identical to your symptoms. A new one from Abbey sorted me, but i needed to have the car plugged into a Consult to diagnose it. Had tried coils/ignitor/plugs to no avail. I dont know how you can test the CAS, sorry.
Thats what someone else had suggested to me as well. Im testing out someone else's coils later this week so hopefully that will indicate whether its the coils. If not I'll have to get a new CAS I guess? What did Consult tell you? Did it tell you that it was bad, or just by process of elimination you figured it out?
 
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