How to run LS1 Coils

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AceInHole
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Post by AceInHole »

tastyratz wrote:I wanted to take a moment to clarify some earlier information. I switched over to ls2 truck coils (the ones with the heatsinks):
When people say the colors are reversed, it means the wire for #4 goes to #1, and #3 goes to #2. Harness is fine.
I changed from ls1 coils and all I did was swap the order of my plug wires - car fired right up after and ran mercilessly. No swapping inside the aem of pins for triggering, no switching positive to negative triggering, nada.
By plug wires, I hope you mean harness power, signal, and ground wires. The coil to cylinder relationship doesn't change.

Just clarifying in case someone reads quickly and gets a bad idea :P
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tastyratz
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Post by tastyratz »

Evil: You really want to run very close to the same dwell time on ls1 AND ls2 coils - I actually would run a touch lower on ls2 coils- I cut my dwell 8%
The wizard ls1 coil dwell timing is a JOKE. Nobody should be using the ls1 wizard - the ls2 wizard is very close to what I run and will be fine for ls2 coils. Set your dwell max to 15 teeth so you can hit the right charge time and keep under the 65% duty cycle recommended.
Its pretty universal between the ls1 and ls2 dwell timings - only difference is how much raw spark you get.


Also: Ace is right, that's what I did. I am having a "lovely" time right now. Car is running like crap and I swapped the coil to cylinder order as they are mounted on the brackets. I think that part is true when using a factory subharness. I changed no wiring though, so I will be taking a multimeter to check my pinouts and confirm
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Post by EviltoM »

I just put LS1 coils on my buddies 2JZ and used the wizard and the car runs amazing...
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Post by tastyratz »

try the ls2 wizard.
The car would run even more amazing then.

I couldn't believe the difference in spark, truly.

Also just to update the thread:
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My friend mike grabbed the subharness connector pinout from gm fsm's. Apparently the sub harnesses are the same on everything but the 8l big block... BUT
The wire order is reversed depending on whether or not you get a left or right bracket. Reversing the plug wires was correct for me - but it had nothing to do with ls1/ls2 coils - only having a right or left bracket coilpack switch.

Another point was raised - my issue might be ground related - He is telling me the factory coils are grounded via the bracket and I don't have mine mounted securely. I'm going to check it and confirm/deny next time I am at the car
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Post by Walperstyle »

This is some pics of my checking things out, being left and right side Coil banks can be different!

When I purchased all my stuff, dude on ebay with the LS1 coil bank also had the connections and the bracket, so I figured I'd check out to see what I had, left or right side, and make a basic diagram that even a space cadet can figure out. The diagram on the notepad shows how thins are wired based on position of the connections/plugs. Hope you can see this to make it out from upside down, or what-not.

You need a multimeter, and a beer, and about 10 mins. 3 beer is much more fun but can change the accuracy.

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so that means my control wires are - and / and [] and I symbols

basically the 4 inner ones on the plug as it sits face clip upward. That are the only individual wires in the bunch, specific to each coil output
Last edited by Walperstyle on Wed Jul 11, 2012 8:00 am, edited 1 time in total.
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Post by ka24detkyle »

tastyratz wrote: but now I noticed the ls2 truck coils I actually have a lot of misfires/stutters/etc.
I just wanted to confirm something on the LS2 coils.

LS2 engine was available in the following:
05-07 corvette
05-06 SSR and GTO
06-07 CTS-V
06-09 Trailblazer SS

So with that being said, is it safe to say that you have the trailblazer SS coils. That's the only thing truck related i see. Or do you have an actual part number for the LS2 coils that have the heatsink you mentioned?

Also,
Does anyone have an AEM part number for the CAS sensor others have used?

Thanks,
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Post by tastyratz »

just call AEM for the part - no real part number per say.
d585 truck coils are the best ones to use with the hottest spark if you setup dwell right. Mike came out of a yukon or a denali or something - d585 should get you the cross references you need.
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Post by ryans13 »

how hard is the wireing to the ecu? does it have its own connector to run the coils or does it use oem harness wires? i just picked up a aem, havnt got it yet, but am finding the parts to run ls1 coils
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Post by KA24ETZTM »

Just curious cause Im wiring up my LS1 coils at the moment. BTW this is on the SOHC. Cant I just use the 12v ign switched source that powers the original coil for all the LS1 coils? This wire runs from pin 36 directly to the coil and the ign source is spliced in. That is whats on the factory wiring diagram. Just figured this would be a bit easier instead of wiring it to the alternator or other source. The wire is already there so why not use it. Also doesnt pin 1 which is the white wire or power transistor wire goes to coil #1 signal. Just wanted some verification. Thanks :D
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Post by tastyratz »

oem coil wire can go to coil 1. Personally I ran all 4 new wires to the ecu since I was running 3 others ANYWAYS... Just for consistancy.

And you need to run a fresh wire for the charge. I am not sure if the old factory one can handle the charge but I wouldn't risk it.
Its just an extra couple minutes I would just run everything fresh so your not chasing quirks down the line.
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Post by KA24ETZTM »

Im running 3 new wires to the ecu for the other coil signals. The power wire that supplys the factory coil comes straight off the alternator. Its like a 14 gauge wire so it should be fine. Another question tastyratz. I know your running individaul coils. How did you get your factory tach to work. From what I understand the factory tach signal comes off the negative side of the coil. This is probably going to be a problem. Am I gonna need some kind of adapter? What did you do? BTW Im running a Haltech Platinum Sport 1000. I really need help on this one. Haltech tech isnt available until Monday and Im wiring this thing up now.
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Post by KA24ETZTM »

:idea: Just had an idea. I ran into this problem doing an SR swap once. If this is the case with the tach signal coming off the negative side of the coil, couldnt I just use a DOHC cluster since there signal works off of a square wave pulsed signal? Then I could just wire the tach signal wire to the Cam Angle Sensor :D Did I just answer my own question. lol
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Post by tastyratz »

I haven't fixed my tach yet actually... my laptop tells me my rpm and almost never look so I have been lazy.
I don't think that will work though because your now tying the ecu into the signal of just 1 cylinder instead of 4 - so you will likely read 25% actual. My plan is just to use the tach output wire of my ecu.
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Post by KA24ETZTM »

My thought was to use the DOHC tach. Which is the same as an SR. With my ECU set to Direct Fire ignition I would think when given the right signal from the Coils or maybe the CAS it will supply the output. My ECU has a voltage output adjustment for tachs from 5-12v as well as a duty cycle and pulse per cylinder setting. I think this may work. Another question does the y/r wire from the ECU go directly to the tach on dual cam KA's I looked at a diagram but just wanted to make sure.
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Post by AceInHole »

Update to the LS7 Coil Swap:

Finally fixed all the coil issues that I'd been posting about earlier. For about the past year I've been band-aiding my setup to keep spark from "blowing out". Finally got the car to get up to 19psi without hiccuping.

Previously I had coil dwell on the AEM EMS set to the AEM Wizard for the LS2 (Corvette?) coil packs, with Dwell Max at 15 teeth and Dwell Min at 0.45 teeth. My Ign Phasing was set with Ignition Sync at 24.00 and Pickup Delay Comp at 40.00 uSec (might've been that way when chasing down problems with timing drift).

Going back to this thread, I changed everything to the original poster's settings, which didn't quite work for my S14. Loaded up my original settings and only changed Pickup Delay Comp, Dwell Max, and Dwell Min (to 0 for Delay Comp, 4.5 for Dwell Max and 0.05 for Dwell Min). Took the car out for a test run and hit 19psi on the first try without any hesitation. Looked through the log and found some knock, indicating my previously safe maps were now advanced. Tuned out the knock by retarding the timing maps and it seems that I'm below what I figured for ideal timing.

Here's my theory:
Dwell Max and Dwell Min probably have less to do with it, but does anyone know the max duty cycle for the LS coils? I calculated it out and found that the Dwell Max at 4.5 limited my Dwell Time right around where the bulk of the hesitation started. It made me wonder if I'm over-loading the coils, but I guess that's easy enough to test out.
Pickup Delay Comp seems to be the big fix. It makes sense that reducing the Delay Comp advances my ignition, and the previous problem was probably made worse by adding the Delay Comp in in the first place. What most likely started as weak spark (found that I was getting 13v to the coils at one point, so direct wired it to get a full 14v from the alternator) turned into the ignition falling out of phase or sync when revving the motor quickly under load. My guess is that it was retarding timing exponentially compared to the linear timing drop under load (so instead of pulling say 1deg per psi it may have been 3 or more). It may also be that the Delay Comp is affecting timing dynamically as RPM changes, so revving quicker under higher loads pulls more than "slower" RPM changes under lighter loads (lower boost).

That's about all I've got for now. I'm hoping to get at it more later, and test to see how much plug gap I can get away with now that I *think* everything is working properly.
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Post by Bleak »

very cool, ty for the info/writeup.
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Post by AceInHole »

I finally ditched my LS2/LS7 coils (GM# 12573190). After going through all my settings and wiring, I wanted to start with new coils. I bought some AC Delco D585 (also under Wells C1251 or GM# 10457730) GMC Yukon LS2/Truck Coils, made a new bracket, and plugged them in. These are the round coils with the aluminum heatsink on the back/bottom.

The result was a night and day difference, and my car is boosting to 17psi without hesitation. I've also upped my plug gap to something normal (0.029) from my bandaided 0.018 gap and it's still going strong.

Conclusion: Either my coils were shot or just buy the truck coils to begin with. Mine were $45 each from Autozone and I was able to pick them up the day after ordering them in-store.
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Post by s14det »

Just wanted to verify that the factory tach will work after swapping out to LS2 coils with the AEM? I read in 1 post that stated it would not work, but did not read anywhere stating that the tach would or would not work. I hope to have my coils installed very shortly,
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Post by EviltoM »

Yes the tach will work, it comes from the ECU.
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Post by s14det »

I kind of figured the tach would work but just wanted to make sure.

Does anyone know if the LS coil setup is the same for the new AEMTuner software (series 2 EMS). I'm getting close to finding out, put I am at the point of switching out the plug wires terminals to fit the LS 2 truck coils and would be nice to know that the LS coils set mentioned on page 1 also works for the new AEMTuner software. There is coil phasing which I set to the same as the injector tooth setting.

Coil 1 0
Coil 2 18
Coil 3 6
Coil 4 12

Which I would think would match to the corresponding Injector Phasing but they do not
Injector 1 12
Injector 2 6
Injector 3 18
Injector 4 0

On the first page it does not mention coil phasing for AEMpro so this is what is throwing for a loop and stopping me from trying the coils out. I can always put it back to the way it was but hoping someone may know before I start swapping out the plug wires terminals. The reason why question this is because I looked at the SR base map as the coil and Injector phasing match (coil 1 / Injector 1 set to 0, coil 2/injector 2 6) maybe not the exact # but they both have the same phasing settings.
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Post by s14det »

Settings are the same for both AEMPro and AEMTuner. I set up my LS2 truck coils the same as on page 1 and used the Wizard for the LS2 coils. I set Coil Phasing the same as Injector Tooth just fyi, Everything works perfect up to 10psi (highest I have tried). I also have the Boost-a-spark connected to the coils so after 4 psi they get a bump in volts to about 15-16 volts or so. The boost-a-spark dial is set to half-way. Going to put back in the E3 spark plugs which are gapped at .040 and should run awesome. That setup ran great when i had the Calum ECU in there. Now with the AEM and the LS2 coils it should be even be better aka hotter. I was running up to 22psi with .040 gap and never had any issues with spark blow out, of course the internal coil would die every year or so with the Boost-a-spark.
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Post by sanitys »

Thanks for the write-up. I install was pretty straight foward. I used the ls2 bracket and harness.

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Post by alloutmotor »

i followed the instructions on the first page on my sr20de fwd. i am using the aem 24-1 cas disk on a 1611 and all my coils fire at the same time :/ i have the phasing set up as per the instructions, i have no clue where to start. i get stat sync my injectors fire my coils fire (all at the same time) but i have a no start condition. for some reason i think everything is out of sync.
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Post by EviltoM »

Sorry for the late reply, but better late than never! Your timing is probably out of sync. Make sure your distributor is installed properly, you can check how to do it in the tech section, and from there you can fine tune it with the AEM. As long as you have it pretty close to where it needs to be it should start, then you can sync it 100% using a timing light. If your using an sr20de you might as well use the factory sr20det AEM settings, and just enable the 3 other coils, and make sure the firing order is in the right order. Also use the AEM trigger disk instructions to set up your cam/crank settings as they are completely different from the sr/ka cam/crank settings.
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Post by LS14 »

What about running LS1 coils on a car that already was equipped with coilpacks (Y33 a.k.a 97-01 Q45)? The coilpacks on this gen Q45 are by far the most common problem and new replacements at cost from Infiniti are $100 each.

The coilpacks on the Q have 3 wires: a chassis ground, a 12V source, and a signal from the ECU. From FSM: "The ignition signal from the ECM is sent to and amplified by the power transistor. The power transistor turns on and off the ignition coil primary circuit. This on-off operation induces the proper high voltage in the coil secondary circuit."

The LS1 coilpacks have 4 (Ground, Ref. Low, Ign. Control, and 12V). Would I just ground the ref low and run the other 3 as they are on the Q45?
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Post by Matt Cramer »

LS14 wrote: The LS1 coilpacks have 4 (Ground, Ref. Low, Ign. Control, and 12V). Would I just ground the ref low and run the other 3 as they are on the Q45?
Yep. If possible, ground Ref Low to the ECU's sensor return wire.
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Post by Jus14 »

I Have a internal coil...so where would the "grey" wire connect or Coil #1 in otherwords seeing how i dont have a main coil wire? Thanks ahead i seen a few that said they had done it but no info on how on that part lol
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Post by LS14 »

Matt Cramer wrote:
LS14 wrote: The LS1 coilpacks have 4 (Ground, Ref. Low, Ign. Control, and 12V). Would I just ground the ref low and run the other 3 as they are on the Q45?
Yep. If possible, ground Ref Low to the ECU's sensor return wire.
Would you clarify "sensor return wire"? Not really following. Couldn't I just combine the two (Ref. Low and Ground) to the original Infiniti ground?
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Post by Jus14 »

Bump for a reply......last two questions
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Post by alloutmotor »

would any one have any idea why my timing light wont work so i can sync my timing i have the ls1 coil setup and hte car starts and idles
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