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Any reason I couldn’t use one of the oem coil power (Pin C) to trigger the relay for the smart coils to get power off the battery? Would make for a cleaner harness. Sorry if this was already mentioned, but I didn’t see it.
It was discussed in the prior dozen posts. at least ...
Perhaps I should rephrase as it most certainly wasn’t discussed, I just read the whole thread again. I’m using a separate relay mounted to my coil bracket. Fused power from the battery to the relay and then on to the coils. So I’m suggesting using pin C from any one of the oem harness ends to engage the relay. Unfortunately I’m trying to finish my harness in the garage but the car is outside and it’s -20 and a blizzard, so testing the pins isn’t possible. Idle hands won’t allow my to not do what I can.
I’m fairly confident this will work and make for a cleaner install. Figured by asking I could possibly help someone else.
Apology for my misunderstanding. Pin C on the OE harness would no longer be used because you’re supplying power direct from the battery now. The power on Pin C comes from the ignition relay. So it would be entirely appropriate to do that. It might depend where the relay is located though. If you have in near the LF fuse box I might be inclined to tap a new wire directly from the ignition relay power trigger there rather than loop it out through the original wiring. I might also be inclined to depower the Pin C wire rather than have it out there hot. The same wire goes to the OE condenser, but it’s not doing anything without powering the coils on the Pin C wiring loop. Sitting out there hot and unused only leaves it as a potential short circuit.
So I’m finally installing my smart coils and have zero output from them. I’m just holding the spark plug against the block to confirm. The old coil fires fine this way, which leads me to believe either I’ve done something wrong or all my coils are bad. I did buy them used, was told they were installed but never used and they appear brand new.
Power is run off the battery through a relay, power is maintained while cranking. All 3 grounds have good continuity and go to the battery, housing, and OE harness respectively.
The signal wire, Pin A on the OE harness only shows about 0.1-0.2v when cranking though. This is tested at the OE connector and confirmed at the end of the new harness.
It’s my understanding that this should be sending 5v to trigger the coil to fire. What would cause this to be so low? Perhaps the signal is too fast for my digital multimeter to read?
Any thoughts on what to try next would be greatly appreciated. And happy new year everyone.
Pulled a coil from another car that works and tried it with the same results, so it’s got to be something to do with that weak signal wire. Unfortunately searching only results in a thousand posts of people with bad coils being told to replace them.
You’re not getting a signal at all on all four pin A connections?
nothing near 5v. But the oem coils fire fine. I’ve gone through the wiring all day, I’m quite certain it’s connected properly. I don’t know what else to do/try
Depending on what you are using for a meter you may get varying success with the trigger. You are much better off with using a scope to see what is going on..
Depending on what you are using for a meter you may get varying success with the trigger. You are much better off with using a scope to see what is going on..
Had to google what a scope was. I can have this one from amazon in a couple days, should be useful.
STARTO Digital Oscilloscope Kit Handheld with Power Supply and BNC-Clip Cable Probe(Assembled Finished Machine) Q15001
In the meantime, any ideas why the trigger signal would be low? And if it’s not low, and I’m just not able to read it because it cycles too fast, any ideas why it’s not triggering the smart coil?
It’s very on/off, not constant like a battery voltage. Think about how quick it has to trigger on/off at redline. It might be too quick to register on a typical VM.
It’s very on/off, not constant like a battery voltage. Think about how quick it has to trigger on/off at redline. It might be too quick to register on a typical VM.
Also, what actual “smart coils” do you have?
That's a good question. They dO make a coil that looks the same without an ignitor....
if you can swap the stock coils back in and they work I wouldn't bother buying a scope... I would look at the coils and the wiring. Make sure the grounds are wired properly. They fire based on the voltage difference between the trigger and the reference ground... so if they are wired wrong they might not fire
It’s very on/off, not constant like a battery voltage. Think about how quick it has to trigger on/off at redline. It might be too quick to register on a typical VM.
Also, what actual “smart coils” do you have?
They are branded Performance World, it’s a fairly common brand here in Canada. They show no signs of being a knock off. I considered this though, which is why I pulled a known working AEM smart coil from my other car which proved to also not output anything.
That's a good question. They dO make a coil that looks the same without an ignitor....
if you can swap the stock coils back in and they work I wouldn't bother buying a scope... I would look at the coils and the wiring. Make sure the grounds are wired properly. They fire based on the voltage difference between the trigger and the reference ground... so if they are wired wrong they might not fire
I have swapped a stock one back in and it seems to fire fine. I was thinking maybe the stock one requires a weaker signal to fire versus the smart coil. Otherwise I must have something wired incorrectly. Perhaps my grounds to the housing aren’t clean enough for good contact, I’ll double check continuity on all the grounds to the smart coil connector.
I also found the number of ohms it’s supposed to be between all the pins on the coil, so I’ll check those. But like I said, getting the same result from a known working AEM coil tells me the coil isn’t the problem.
sorry, you did state where you were measuring previously. It seems most likely to be a ground wire imo. Because that boils down to being the only difference between an OE vs IGN-1A coil setup.
Only other possibility; did you verify that each wire in the adapter harness is connecting to the correct pin between the OE connector and the coil connector? Because it’s not clear whether you made it or bought it somewhere. You probably checked that already, just making sure though.
Ok, so I’ve figured It out! First off thanks guys for talking this out with me.
So my Pin A and Pin B were wired according the diagrams posted a few pages back. Pin A, the middle wire on the OE harness should be the trigger wire, also Pin A on the coil. All 4 “A” wires are different colours, where as the “B” & “C” wires are the same respectively. So once I’d found Pin C by finding the 12v constant, I’d determined Pin B to be the other side of the connector and wired them all accordingly.
However, while checking my grounds, which all checked out for continuity btw, I decided to check continuity between like pins on the OE harness. B-B had no continuity to each other, which seemed weird as typically sensor grounds splice together from multiple sensors back to only a couple wires to the PCM/ECU. C-C, the 12v constant had perfect continuity as expected between pins. But the supposed trigger, Pin A, when tested A-A had perfect continuity too. Pin A also was the only pin to have near perfect continuity to the negative battery terminal (0.004), the others had none.
Above tests were done with the key on.
To me I figured Pin A & B should be switched if I forgot about any diagrams I’d seen and just went off my findings. I used a couple wires to patch between harnesses, and the car fired up instantly on one plug, lol. I didn’t have a helper, so I hooked up a plug wire and a timing light so I could confirm output. The fuel relay had been pulled quite a few cranks ago, UIM was off, really didn’t expect it to fire! Now to de-pin connectors without breaking anything and swap A-B.
Still scratching my head as to why my setup doesn’t jive with the OE schematic posted a few pages back. But I’ll take the win!
Thanks again, your questions got my brain firing on both rotors, haha.
These are the resistance numbers to test between pins given to me from AEM to test their Smart Coils.
A to B = 10k Ohms A to C = 0k Ohms A to D = 36k Ohms A to E = 16k Ohms B to C = 0k Ohms B to D = 45k Ohms B to E = 26k Ohms C to D = 0k Ohms C to E = 0k Ohms D to E = 20k Ohms
The AEM coil I had off the other car for testing matched these perfectly, the Performance World ones did not. Definitely not identical coils. But they do fire now, so I’ll see how they perform shortly.
The OE wiring spec shown is from an early pre-production electrical manual found online. I’ve warned people a lot in various threads that they need to use the specific service and electrical manuals for their particular model year in order to have the most accurate information. That usually means buying the paper books, which are a bit costly. Anyway that all makes sense now.
The problem with plug diagrams.... some are looking into the connector... and some are looking into the coil. This will result in horizontally mirror image wire layouts and that doesn't work well...
For the record can you verify which model year RX-8 you have? Sounds like it must be a CADM (Canada) model too?
Also curious which part number coils you have? I see Performance-World mentions a #4253 Rapid-Fire smart coil in their product detail for a coil mount, but doesn’t actually have the coil for sale on their website. I couldn’t find it offered anywhere for sale either. Any additional info is appreciated. Thx.
Also, due so many copycat/fake coils on the market I’d recommend contacting Lance @ PanteraEFI for obtaining the real deal directly. It won’t have a fancy label or cool colors, but he is *the* main source for genuine IGN-1A ignition coils.
The coils are PW 4253, and I too noticed they’re no longer on their website.
I’m aware of the amount of knock offs out there for smart coils. The only difference to my genuine AEM 30-2853 coils is the epoxy is black vs clear, and only two pins holding down the heat sink vs four. The heat sinks are not painted but identical matte finish to the AEM’s. They also weigh the same, where most knock offs are quite a bit lighter. They do however ohm different then the AEM’s as noted above. So there is some difference, but there could be some differences between AEM/Holley/Mercury or your guys. I’ll be able to test them out driving in a few days.
11-09-2019, 07:05 PM
