As subject line says
Does anybody run aftermarket ignition box with stock coils???
I have AEM CDI, when I try to run it I get huge arcing under the stock coils. My option is either to buy new stock coils ($350) or set of aftermarket coils for $150-180.
I prefer to stay with stock configuration because AEM CDI had some issues, it burned on few people cars. I don't want to be stranded somewhere far away from home. With stock coils I can return to stock ignition by inserting bypass plug into the harness
Thanks
Vladimir, 89T

Hello Vladimir

Well, lots of people seems to have problems with the earlier versions of AEM CDI, however I had the impression that you need special coils designed for CDI and I'm not sure that you will ever get the stock ones working. Most people with CDI go with MC coils (COP) when converting to CDI.

BTW the stock ignition system is pretty strong on a Mk III, I have been running 34 Psi of boost with my T-66 and completely stock ignition system and I'm yet to hear miss. Hell, I even run it with some old/cheap aftermarket spark plug cables and it work absolutely flawlessly.

Regards
Karsten Horn

mm...karsten is right...wth the aem cdi, u will most likely have to change to aftermarket coils...i dont know of anyone with an mk3 that has actually gotten it to work with stock coils...even though teh stock ignition is pretty well made....i know of people doing it with nissans, but once i put in my msd ignition pack i changed teh coils as well...well i actually got it as a package, with the cdi...u might be burning through stock coils pretty easily...though i might be wrong you might want to check someone with the cdi setup

Thank you guys for the input. I see definitely I have to buy aftermarket coils, this is also more cost effective solution.
Any idea if aftermarket coils work with stock mk3 ignition? Do I have to look for coils with similar to stock primary winding resistance?
I am asking all these things because AEM CDI can't be relied on, on some people's cars it burned after 2 hrs of work. Other folks run it without problems
Better be ready to return to stock configuration any moment. Than I have to keep stock coils and harness in my car
Thanks
Vladimir, 89T

Hello

As long as the aftermarket coils have the same resistance specification they should work just fine.
The only reason to go the COP route on a 7M-GTE should be for visual purposes as the stock system is indeed very strong.

I've used the CDI with the stock coils, but I used AEM EMS, so the stock ignitor was ditched. I now use CBR 600 F4I coilsticks with the CDI, and it works great. The coilsticks should work with the stock ignitor as well, just run the coils in series, 1+6, 2+5, 3+4 and it should work fine.

I've used the CDI with the stock coils, but I used AEM EMS, so the stock ignitor was ditched. I now use CBR 600 F4I coilsticks with the CDI, and it works great. The coilsticks should work with the stock ignitor as well, just run the coils in series, 1+6, 2+5, 3+4 and it should work fine.

Hello

I'm not positive that the CBR coils will work with the stock 7M ignitor as we do not have a stock CDI ignition. There is a BIG difference between ordinary coils and CDI coils - have you tried to use those coils with the stock 7M ignitor?