So there I was,

On my way back from a road-trip when my Crane Cams HI-6 ignition box died. I wired the harness back to stock setup, by-passing the ignition box and the car fired right up allowing me to complete my trip.

However, past 5500rpm under WOT it now falls on its face and misses. I'm assuming it's spark blowing out. I'm currently running plugs gapped at .035 and am thinking about gapping them to say .020 temporarily just to aid in trouble-shooting this miss.

My question is, is it possible to gap the plugs too tight in effect creating a negative latent effect I'm not aware of? I'm planning on getting a new ignition box in a month or so (still debating what route I want to go: retard capabilities, etc). For now the car drives fine until 5500, but I would like to remedy this spark blowing out w/stock ignition if possible.

Relevant Engine Info: 396, 9.0:1 CR, 6psi @6000rpm, NGK TR6 Plugs, Taylor 10.4mm wires, MSD Blaster Coil, GM opti-spark, rest of igntion system bone stock. Snow performance Meth/Water Injection system 675ml/min single nozzle at 150psi @ 5psi. Currently spraying pure water for detonation resistance.

Thanks ahead of time,
Andrew

 

Well even though nobody's posted yet, I'll update.

I re-gapped plugs to .025 and it still and misses at about 5500-6000rpm, you can hear it pop in the exhaust. Doesn't show any knock on the scanmaster. Engine free-revs fine, and under light throttle you can bring it through the rev's just fine.

I have a hunch without an ignition box the spark is simply blowing due to the combination of boost, and water injection.

If anybody can confirm this thought, or if I'm completely wrong...please let me know.

Thanks,
Andrew

 

I can't diagnose your car over the 'net. But I think that is exactly what is happening. Well, maybe not "exactly" in the sense that I think a miss under these circumstances is because of a weak or non-existant spark, not "blowing out" per se.

Rich

 

Ahh ok, I guess I will simply be buying a new ignition box sooner than later is all. I'll update if it's the "cure-all" to my sparkless woes.

Thanks,
Andrew

 

Wired in a new MSD 6A tonight. It fixed the problem.

Runs like a top through the whole rev-range. Feels good.

Figured I'd update.

Thanks,
Andrew