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Help with spark plug diagnosis, failed after 1 week
Okay, so I threw in a brand new set of plugs last week. They last exactly one week before they went back to a no start. Now, I am going to post a picture of them as I just pulled them. Heres how they are arranged from left to right: L2, T2, L1, T1. I am fairly certain that L1 wasnt even firing. The coils are of unknown miles, so likely the coil is no good. I swapped in a cleaned set of plugs (cleaner with a harbor freight spark plug cleaner, dont judge me), and reinstalled my DIY LS2 conversion kit. It fired right up. But I am worried about how these plugs came out. Should I be? Also, T1 came out with the outer porcelain cracked, and I dont remember if I dropped it or not. Is there any way it could have cracked while installed?
Last edited by ShadowGryphon; 11-03-2017 at 06:40 PM.
Likely you cracked the insulator installing or removing the plug. It's easy to do on that plug unless you use a good u joint and are really careful.
the L1 plug looks like the coil wasn't firing like you said. Looks like the plugs are a bit fouled. ...drive it harder 😉
I'm going to park it and save up to get a brand new set of coils. The DIY LS2 conversion kit I have doesnt want to cooperate either. That might be due to where I grounded the kit, so I will try that first. As for new coils, I know everyone says BHR, but I also see the kit that SakeBomb Garage has with the IGN-1A coils. So I dont know which kit to go with. Any suggestions?
Oh, and those plugs only have like 15 miles on them lol.
Lol, luckily the 8 is not my daily. Its a project. Been a fun one too. Was finally able to drive it to work last week and everyone of the guys I work with who always rags on it actually said they can see why I havent given up on it.
Well I also admire your resolve, but it’ll be interesting to see how many more years you’ll devote to fumbling around with this before coming to the realization that car modification/repair might not be your calling ...
Well I also admire your resolve, but it’ll be interesting to see how many more years you’ll devote to fumbling around with this before coming to the realization that car modification/repair might not be your calling ...
Assuming you actually have LS2 coils, they’ve never been the correct coil to use on an RX8
By day I am a technician for Nissan. I work on the 8 in my spare time, meaning I can sometimes go months without having time to work on it. Now, I will browse the forums for issues similar to the ones I see and post asking about parts, but the majority of everything I have done on this car was needed. Fuel pump outlet was broke, went used, then brand new when I realized the used was bad. Coils, plugs, wires were replaced because I didnt know when they were last changed. Again, due to budget I went used and those worked for a while. Injectors were sent out to be cleaned, flow tested, and have all components replaced due to a flooding issue. Starter was extremely slow so I replaced it. Battery was completely shot when I bought the car, so replaced it. I might spitball ideas around on the forums, but until I am 100% sure it might fix something, I dont do it.
As for the LS2 coils, they are D585's. Had everything I needed to make the kit, minus the RX8 coil plugs, from an old project (old because someone hit it and totalled it). I used the D585's as thats what the majority of people on here were using. Was I wrong? Maybe. But I was trying to avoid the oem coil failures associated with high RPM as this car is meant to be for fun, not grocery getting. Now, can you give an honest suggestion as to what coils or aftermarket solution to run? I would greatly appreciate it.
And yes, I do see that buying used parts for this car is probably hurting me more than its helping. Thats why it is a project.
LS2 coils are not D585 coils, hence my choice of words. Please don’t misunderstand my intent. I want to help you, but am unsure if that’s possible. Didn’t I offer to send you a known good ignition system and you rejected it because of some preconceived brand name standard? When I say good; meaning it functions properly. It’s not pretty, there’s no bling, it does work properly though. Or rather, I ran many, many races up to 10k without issue using it. Is that high enough for you? Now my ability to drive as good as the engine ran is a different story ...
Let’s say you buy a new system whether Mazda OE, BHR, SakeBomb, or whatever and you still have same or related problems. Dropping all that dough only guarantees new parts, nothing else. In addition to maybe not even correcting the root problem you do know that occasionally new parts can be defective too, right?
Per your own words “had everything to make the kit”, did you also have this to verify functionality?
I would still like to verify 100% that it is ignition, sure. But I honestly don't see how much closer I can get to that. The plugs in my first post were only installed for a week, roughly 20 miles of actual driving, before they got so fouled they wouldnt fire. That was using a borrowed set of OEM coils. That fouling could be a number of things: fuel trims too rich due to another faulty part, computer still learning, weak ignition, or the fact that I havent done a decarbon procedure on it yet. With a clean set of plugs, the D585's will start it on the third try when cold. When hot it does this wierd half running thing where you can here and feel it firing but it wont stay running without the starter spinning. With my original set of OEM coils it just cranks. Doesnt try to fire, doesnt feel like its firing, nothing. With the borrowed set of OEM coils it will start, with clean/new plugs, but sound like its running on 1 rotor for a half a second before the other kicks in, indicating an ignition issue. Also with the borrowed set it will start when hot with no issues whatsoever. Everything in here points toward ignition to me. But, as it is an engine platform I am still unfamiliar with I could be wrong. Thats why I would prefer to verify the cause. I do remember you offering to send a known good ignition system. But I cannot remember as to why I rejected it. If you are still willing to do so to help me verify 100% that it is the coils it would be greatly appreciated.
And as for my hard-headedness, I apologize. I do suffer from Aspergers Syndrome and at times I can be extremely hard headed as to figuring things out and feeling that it has to be done a certain way or it wont work. I know this is not an excuse, but it is an explanation as to how my mind works.
Yes, a fairly new technician, and still learning. The majority of my knowledge comes from repairing/restomodding a 1984 Chevy El Camino before someone rear ended me in it and bent the frame. That vehicle had a carburetor, a distributor, and a single coils. And 98% of the time an ignition issue on that car was either timing or carb issues. Hence why I mentioned being unfamiliar with working on the 8. And even at the Nissan dealer I work for. I have yet to run into an ignition issue. The vehicles we get that wont start are usually: 1)diesel in a gas or gas in a diesel, 2)key needs to be programmed, 3) battery issues, 4) wrecked and ECM crushed. Not once have I seen one come in with bad coils or plugs. Hell, I've even seen one roll into the shop with a starter on fire cause it was stuck on. And it was still slinning while it was on fire. Everything I do or find on the 8 is new to me, thats why I come here and ask questions. Not just to fix my 8, but maybe to also learn something I can put towards fixing something at work.
Hell, heres a good example of learning something. Before My boss sent me to Dallas for my first training class (basic electrical, which I knew the majority of but they also showed us how to access a better wiring diagram for Nissans), I never would have known that the ground side of a trunk release switch on a Nissan Sentra goes through the passenger front door lock actuator. Or that said door lock actuator has to be in the unlocked position in order for the trunk release to work.
And yes, I do have the tester. Used it on my original set of OEM coils, it produced a weak spark. I have not used it on the D585's or the borrowed set as I have misplaced it.
Last edited by ShadowGryphon; 11-05-2017 at 08:40 AM.
11-03-2017, 06:37 PM
