Here are a few pic's of the plugs I pulled out of the car today. There were nice and golden brown thursday before my track day at Hockenheim. I have been having a High RPM Misfire around 5500-5700 RPM's even before they looked all fouled up. I am thinking coil packs, opinons?

Plugs are NGK ILZKBR7A-8G

 

Are you still running your Stage 3 AP tune, or did you change anything recently?

Mike

 

Still Stage 3. I have been changing plugs every 10-15k miles for about a year now. Every time they look like this. But this is the first time the misfire stayed even without the plugs looking soiled. That is what's making me think the coils are starting to go.

Brian

 

I think that you are correct in your logic. If you haven't made any mechanical or tuning changes recently, wear and age would be the logical troubleshooting step. Since there are limited mechanical components in the ignition system, the coils would be my choice.

I know that Way has found a NGK platinum plug that is one range colder for 'highly tuned vehicles'. I don't know if a platinum plug would be easier to fire than the fine wire or not, but it is something to think about.

You mentioned that the miss is from 5500-5700, does it go away above that, or is it that the RPM that it starts at, and continues until shifting? Is the miss in all gears?

Mike

 

Yeah I installed some Brisk plugs I got from Out-motoring tonight before I left for work. It is raining cats and dogs here so I couldn't test for the misfire. It seems to only be in 4th 5th and 6th. It only happens in 4th when under a lot of load like WOT up a hill type of situation. But in 5th every time. Once it hits its like hitting boost cut. Power is gone and I have to shift. The RPM's don't keep going they just kind of hang there.

 

I hate to say this...
but a stage 3 on stock internals is VERY DANGEROUS to you wallet...
More than a few folks have had a piston fail around the "skirt" area...resulting in excessive blow-by (dip-stick gets blown out, etc).....or complete engine failure..boom!!
Watch out!

 

Thanks for the heads up! I have been running stage 3 for about 15 months now with no real issues related to the tune. I am sure it will happen eventually because of my driving habits. We all know the risk taken when your pushing 21 PSI on stock internals. And we all pay to play.

 

I'm having the same kind of issue right now in 5th gear only. Happens right where you are describing at 5700-redline @ WOT. My plugs have a very light tan haze to them so they're OK. Running the Evolve tune right now and boost peaks at 17psi. Not as extreme as you It's not like there is much more power to be had after 5700rpm but I like to wring it out in 5th gear so when I shift to 6th I'm at a better point in the engine map.

I'm not sure if mine is misfiring. What happens to me during the condition above is that I get a little hesitation and then some exhaust burbling. It sounds almost like some excess fuel is getting ignited in the exhaust path. Nothing severe sounding like a knock. AFRs look good when compared to dyno plots from Evolve. I'm going to try swapping coils at the track this weekend and see if that helps.

 

Yup that is the same symptoms I am getting, but I do get a cel that self clears almost immediately after. I am interested to see how your plugs look after the weekend.

 

I haven't seen a CEL occur. Maybe because it happens within an instant and goes away. I'll post pictures after Memorial Day weekend. What I can say is that my coil packs have quite a bit of rusting on the outside of them when I pulled them out last weekend. I'm betting this is from two years of very bad Michigan winters and rain. I wouldn't think this would affect the performance of the coil but it sure does make me wonder if any moisture got inside the coil pack.

 

I noticed an orange ring around the tops of the plugs as well. Here in Germany our winters are just as bad a Michigan's but we get more rain throughout the year. Interesting to see how it pans out. Maybe we can get a group buy on the okada coils lol.

 

Forgive me if this was mentioned but have you done a valve cleaning recently? I was having similar problems from carbon buildup and ive manually cleaned them every 15k or so. Ive also went through plugs quite a bit. Had the brisk and they never worked right...gapped them according to alta specs and the car pulled hard and stalled at idle. Regapped and had good idle but car felt sluggish amd misfired. I tried like 4 different gaps and it was never as good as oem

 

No I have not de carbonized the valves yet. I have had the PCV delete on for about 15-20k miles and the car only has 45k on it. I am also running water/meth injection. I should take it off and have a look but I am really hoping that's not it.

 

Probably fine but it doesnt hurt to check. I think with the w/m kit you probably would be fine now but before that its possible there is some good build up. Ive seen quite a bit on low miles cars especially when driven aggressively and holding out gears longer/engine braking. I find 15k is about the sweet spot where I start getting some buildup with no preventative measures

 

Thanks for the info. I will have to take a look the next time I am under the hood. Wouldn't hurt to just take a look and scope it out

 

Hey there,

I'm driving a Grattan Raceway this weekend and swapped coils but also changed to colder heat range NGK plugs. I know I was supposed to do the coils only but it only made sense to run a colder plug since my boost is around 17psi. Spikes sometimes to 18 on the main straight. Problem is gone now! I still don't think it hurts to have spare coils on hand since ignition problems happen from time to time and they are a specialty part you just can't find at a generic store.

I got the plugs from Way after he recommended them. They are definitely different than the JCW model plugs. If you do a search on his site you can find them.

I ill still post pictures of the old stock NGK plugs when I get home.

 

Thanks for the Update Shane. This means that I am hopefully on the right track with the coil packs. Since I Have already changed plugs this would be the other half of your solution. Looks like Okada Coils will go on order soon.

 

Ha ha, you caved on Okadas

I just got back from the long drive home from the track. Pretty exhausted. I'll take pictures of my old plugs in the morning.

 

I started getting misfires at 10k miles. After phone calls and dealer trips, I finally found the problem to be a cracked spark plug.

DDMWorks didn't spot it when they had the plugs out and the misfires got progressively worse over time, probably as the insulator crack continued to propagate. When I found it the crack ran the entire length of the insulator.

 

Man that is impressive. I have check them all and no cracks. It seems to have gotten better. I think i may have been over doing it with the meth and running the system too rich. Still not sure.