Ignition problems with HKS FCON Pro (R33 GTSt Spec 2)

[BennyT]

Hi folks,

Spec:

R33 GTSt Spec 2, FCON Pro (piggy back) with MAP sensor, top mount turbo and supporting mods otherwise stock (unopened) engine. I do my own tuning on the FCON and have been running it for a few years. (The mapping is good).

To cut a long story short, I developed some fairly random igition problems at start up / idle and basic driving (no boost). The stock ECU was thowing fault code 21 (ignition) after just firing it up (no driving). I figured I'd do Audi R8 coil swap, since the coils are original anyway (25 years old!). So, with the R8 coils fitted, I fired up. Zero ignition. Engine just turned over, no spark at all. So I removed the FCON entirely to check the stock ECU (switched back to stock AFM) and ... ... fired up perfectly. No error codes thrown.

So, why does the FCON fire the stock coils but doesn't fire the R8 coils? Ignition dwell time is about the same for the stock and R8 coils so shouldn't be a problem. I can only assume the FCON or the wiring harness has some kind of weird problem...

It's possible that the FCON got corrupted somehow but it looks OK on the laptop and it's not throwing any error codes. I'll probably have to check the harness more carefully although I can't figure out how it could have got damaged.

Maybe I should just bin the whole lot and get a Link? It's just a shame they're so expensive...

Thoughts? Thanks

[syd_gtr]

according to https://www.50ignite.com/nissan-skyline-r33-gtr the R8 coil pack is not compatible with some ECUs (fcon not mentioned as either compatible or not compatible). Maybe fcon is also one of them. 

[BennyT]

23 minutes ago, syd_gtr said:

according to https://www.50ignite.com/nissan-skyline-r33-gtr the R8 coil pack is not compatible with some ECUs (fcon not mentioned as either compatible or not compatible). Maybe fcon is also one of them. 

Nice find! Huh, weird. I guess it's possible. FCON Pro is supposed to be a pretty comprehensive ECU (in it's day!). I wonder if anyone can confirm this... ? It was weird there was no spark at all.

[Ben C34]

Did you get rid if the igniter when using the r8 coils?

[BennyT]

SOLVED! (At least partially)

15 hours ago, Ben C34 said:

Did you get rid if the igniter when using the r8 coils?

Thanks, yeh I have spec 2 so no igniter module.

So with further digging it turns out the R8 coils need a lot of juice. I asked a knowledgable chap about the FCON and he pointed out there were some options to mess with the ignition signal. In fact, jumper 11 (J11) inside the unit switches between "normal" and "high" current mode. (I can only speculate that "normal" mode provides some safety in event of a current surge.) Evidently the stock ECU provides enough juice as standard. Anyway, I switched to "high" current mode and it worked just fine.

I still don't know if my original ignition problems have been solved by the new coil packs but this seems like a step in the right direction.

For future reference, I noticed that the stock ECU throws ignition fault code 21 when using the FCON (I think this maybe normal operation due to the by-pass?).