LSx Coil/EPM users READ!!!

[Blacksaleen95]

If any of you have followed my previous posts with timing errors/epm issues... I believe that an issue may have been uncovered using a specific version of the lsx coil.  I o-scoped my signals and got a voltage spike in my crank signal, which would cause the ecu to see a significant edge, give me a timing/sync error and obviously be a big pain in the a$$.  The internal logs would show the crank signal dip, and then the timing/sync error would follow.

What I've discovered (along with billynotnice) is that the consistency with these issues lies in the style lsx coil that was being used. I have setup a few other ls coil'd cars and used a different coil and have had 0 issues. It seems this style coil is causing the issue.... What' I'm looking for is to find out who is using what coils.

This is the coil that is in question, GM# 12558948 :

For the guys who are using lsx coils with an EPM, please list the part number of the coil you're using. I'm hoping that we're able to save some people headaches in the future.

[billyNOTnice]

Guilty 

[IcantDo55]

Subscribing.

So we any more sure of this before I buy my coil pacs?

[Blacksaleen95]

billynotnice is about to swap out to the heat sink style lsx coil....

I'd say get any coil except the one pictured... I know for a fact the other ones are working fine with no issues.

[billyNOTnice]

I will be posting my results as soon as i get the new coils. I will not be changing anything at all besides them. So we shall see. stay tuned.

[Blownstude]

Was going to use #12558693 from a 2001 5.3 Avalanche. Will these be OK?

[Blacksaleen95]

Was going to use #12558693 from a 2001 5.3 Avalanche. Will these be OK?

yep... those have been on the 1401 box aem'd fiero for about 10k now with no issues.

[BigAl...]

I'm glad I stumbled across this thread.  I have (quick setup list) chevy 4.3 v6 running the aem 1902 box with the internal ignitors removed, aem epm and the above mentioned coils ( ) the problem I'm having is, if I lock the timing at any value and put a timing light on it, at first it's on the money but when I rev the motor it walks, it retards upto 15 or so degrees.  this is driving me crazy!

I would love to here the results of your coil change.

TIA
BigAl...

[Blackmagic94]

Ill post up what number mine are, but i know they are off the BBC 8.1L Vortech from 2001-2004 or something on GMC 3500 trucks.

[BlueBlood]

I have been running the #12558948's and everything seems to be ok right now...much better than with the stock dist!! What exactly are you experiencing?

[Flateric]

These are the exact coils that I am currently using on my 2jz swapped supra mkIII and honestly they are working really great. No issues with them at all. Actually my motor seems to run smoother than ever with them.

I am running a Series 2 box though so this may be the difference.

[PQatPIT]

These are the exact coils that I am currently using on my 2jz swapped supra mkIII and honestly they are working really great. No issues with them at all. Actually my motor seems to run smoother than ever with them.

http://www.034motorsport.com/product_info.php?cPath=26&products_id=277

I have recently installed these into four 2JZ-projects and I have noticed this exact same thing. They run smoother, and no ignition problems since.

[4Jenna]

Any update?

I got the 12558693's and wanted to make sure these were still a good choice.

-Chris

[MP Tuning]

I have used every single style of LSX coils with AEM ECU's with zero issues.

If you are running into cam/crank issues, which seem to be related to coils, it's usually because of improper coil grounding. One should always ground the coils directly to the engine block, that way the secondary (i.e. spark voltage) has a short direct loop back to the coil and will not induce a momentary voltage offset at other ground points on the car. These momentary voltage offsets can often trigger the cam/crank inputs on the ECU so you get timing errors and such. (I've worked on car that it's so bad the engine will not even stay running)

Additionally, make sure your are using resistor spark plugs. The resistor built into the plug will considerably reduce voltage spike which can be trouble for cam/crank signals. I have made many non-running engines run like a champ just by switching over the resistor plugs - sometimes after messing with the non-running engine for days trying to figure out what is wrong.

If using an AEM EPM, I recommend using HS (12V+) and LS (ground) outputs from the EMS itself to power it as it removes any possibility of voltage offsets (particularly ground offsets) between the EPM and EMS so you get nice, clean & consistent cam/crank signals. This also makes the wiring nice and neat because all 4 wires of the EPM go straight to the EMS connector(s) without the need of cutting and splicing and allows one to keep a stock engine harness stock!

 

[Blacksaleen95]

If using an AEM EPM, I recommend using HS (12V+) and LS (ground) outputs from the EMS itself to power it as it removes any possibility of voltage offsets (particularly ground offsets) between the EPM and EMS so you get nice, clean & consistent cam/crank signals. This also makes the wiring nice and neat because all 4 wires of the EPM go straight to the EMS connector(s) without the need of cutting and splicing and allows one to keep a stock engine harness stock!

Not sure how many mustang epm setups you've done, but these problems seem to occur with the ford setups. I've o-scoped the cam/crank signals and have seen first hand what the coils give for feedback with all the wiring setups. Could it be ford wiring? Could it be the ignitor in those coils? Who knows, but that is what I was trying to find out with this post. Since most guys are just going with the truck coils now, this isn't as much of an issue.

Also, I'm not sure how you're hooking up the epm to an HS output on the 1400 or 1401 boxes as there is no HS outputs on those boxes.....