Pretty sure it's blown/blowing up...
 

2005 RX-8, M/T, 75k miles, no cat, SOHN adapter, oil changes every 3k, +/- 150 miles.

I recently bought the BHR ignition kit for her. I put it on yesterday, got everything all buttoned up, started the car to the purr of the rotary...all was well.

It started to idle rough, died while cold, and flooded. No biggie, been there done that. Pulled the fuel pump fuse, got her deflooded, started her up, held the RPMs up to ensure she didn't die again (3k-ish). When she was warmed up, I reved it up a touch to 4500 RPM, then the tach started diving until it stalled.

One...two...

POW! Massive backfire (sounded like a 12 gauge firing out of the back of the car) that probably scared the entire subdivision to death. She did start again and tried to run, but began dying and refused to start back. So I decided, what the hell, I'll swap back to the old coils again to see if I got a bad unit from BHR. I did and she started right up, but now she won't hold an idle, runs HORRIBLY with massive power loss, and anything above 4500 sounds like the engine is flying apart internally.

I did my due diligence with searches and Googling the whole site and found many similar threads that point to her being blown up. Just wanted to run my particular tale past everyone to see if there's any hope. I do have a spare car and "oh shit" cash for a RR rebuild if it comes to that, but then it's the small matter of transporting the 8 back to Tennessee for a car swap and rebuild.

EDIT: Trouble codes P0296, P0171 (been fighting this one for a while).

FWIW I don't think your symptoms guarantee a blown seal. But when something like this happened to me a while back, I pulled the spark plugs and the shrapnel on the rotor 2 plug was what ultimately clued me in. I don't have a rotary compression tester, either, so the standard answer of "get a compression test" wasn't so helpful.

I've been prepared for it to go for a while. I've even been a bit suspect of it going downhill the past few months, so if it is the worst, the only real annoyance is the fact my spare car is 500 miles away atm.

Yeah lol I can see that as being pretty annoying. When it happened to me, my spare car was also a couple hundred miles away. Annoying is one way to put it...

What was "wrong" with the car that prompted you to invest in the BHR kit?

This may be a dumb question, but are you absolutely sure you had/have all your wires routed correctly?

Nothing really, aside from wanting the peace of mind.

Yes, all wires were in the proper places when it was started up. I noticed on my final inspection before startup I had the rear leading and trailing wires crossed up, but, again, that was caught before I fired it up.

Pretty sure it's blown/blowing up...
 

First, are you sure all coils and wires are connected securely and properly? Did he wires "snap/click"?
Second, did you unplug the battery? If so, the car requires a few drive cycles to relearn fuel trims. This can cause you to stall out.

When it goes, it goes. But, before you jump to conclusions you need to troubleshoot. If you can get it to idle then warm it up and get a vacuum reading with the engine warm. if the vacuum reading is below spec then you should probably make a trip to the dealer and get the engine compression tested before you waste any more money.

They all clicked. I made triple sure of that. Didn't unplug the battery. I've done the fuel trim relearn a few times and this definitely isn't right.

@9k I doubt I could even get it to the dealer without a tow. When it finally turned over and ran, I could barely get it around the block. But I'll go for that first, for sure.

You should always unplug the battery when doing work to your car. Could cause a short.
I recommend unplugging it for 5-10 min, then hook it back up, then do a few drive cycles (bring to operating temp, allow to cool, then repeat. This could be 2-4 cycles).

Otherwise, as 9k stated, do some more troubleshooting before you bring it in. It could be something simple, or it could mean a new engine.

I'll give it a go tonight. Worse comes to worse, at least RR is practically in my backyard back in TN.

Thanks everyone for your input. I'll keep you posted.

Update: removed the neg cable for ten minutes...she'll at least idle hot now, but I'm unable to pass 4k RPM on the road (no problem at idle speeds). Compression test scheduled, dropping the car off tonight.

Still starts up like shit, takes a few seconds hot. I'll retry cold later because I honestly can't remember if it was quick or not.

EDIT: Fixed...prepare for laughter. Two of the plug wires were crossed up at the coils. :wallbash:

Thanks again, everyone. Still going to do a compression test anyway, but at least I know it won't fly apart going there.