First off a quick thank you to the veterans of these forums. I’ve been lurking on the forums for about 5 years and owned my RX8 for about 3 years now. I’ve read hundreds of threads that have been very informative and helped from picking a car to rebuilding it. I wouldn’t be able to own this car without these forums.

I had my engine rebuilt by Rotary Resurrection (+1 to his many recommendations on this forum). The engine failed ultimately from a clogged cat, but I am pretty sure coils were the primary failure point. I bought the car cheap at borderline compression numbers, so this has been planned, and I’m a bit surprised it lasted 2.5 years in the condition it was. While I had the engine out, I took the opportunity to install a few aftermarket parts, which I’ll list below. The only really relevant one is the ignition, but for completeness:

Aftermarket Parts:

• BHR ignition (+new plugs)
• BHR midpipe
• BHR engine mounts
• ACT Flywheel (Mazda CW)
• Exedy stock replacement clutch

The main issue I’m having is a P0302 Cyl2 (rear rotor) misfire. It occurs at high load/rpm most often, but I occasionally get a blink at idle. I have not confirmed if the idle misfire is more likely immediately after a high load/rpm scenario. For example: sitting in the driveway, I can rev to 9k with no problem. Doing a second gear pull will cause a flashing light continuously about 80% of the time.
Obligatory link to the Misfire Thread in case anyone got here and hasn’t read it.

Steps I’ve taken:

• Tested the BHR ignition with
  this
  this
  tester
  
  • Checking the plugs, the cyl 2 ones I pulled had a bit of carbon, not much. I will replace them again when I solve the issue. Unfortunately, I didn't think to check the front rotor to compare.
• Cleaned fuel sock (was fairly dirty)

Steps I plan on taking:

• Confirm fuel injector wiring.
• Replace SSV actuator
• Check SSV Solenoid
• Replace fuel pump assembly

Symptoms: (ie every little thing I’ve noticed)

• P0302 Code - no jerking, etc
• Very Slighty rough idle – there is a “burp” about every 3 to 5 seconds. I have no idea if this is normal or not.
• SSV ticking – checked for vacuum response. Seems to start moving at less than -3.6 kPA. The way I read the manual this is out of spec.
• Whine/ tone coming from fuel injector area of engine bay. I haven’t diagnosed the source.
• Slight hiss coming from purge evap sol area (I have a purge evap code. Planning on replacing next time I remove UIM, but not positive the noise is related.)

Any recommendations on order for troubleshooting or something I have overlooked is welcome. This scenario is a bit different from most misfire posts I've read through because I have to also consider all the ways I could've fucked up the reinstall. I have ruled out ignition for now (maybe incorrectly). I also don't think its intake related as I've been over the system checking for leaks. My LFT is ~8 ~4-5. I'm trying to compromise cheap, easy, and most likely in determining order of attack. I'm running out of easy, so I'll be digging in a little deeper soon. The load dependence biases me toward fuel system, but only getting the P0302 means its likely only affecting cyl2. That said, I just found the SSV issue and am not sure if it is related yet.

UPDATE SOLVED:

Life has been hectic and money tight the past few months, but I finally got around to the car again. In this time, signs of alternator voltage issues cropped up and, sure enough, the regulator was bad. I replaced that alternator and some other bits (including purge valve) in the apartment parking lot. Sure enough, the misfire is gone and the only code is from me missing a cat! It seems the alternator was bad the whole time and wasn't driving the new BHR coils properly. Thanks again for the suggestions and willingness to help!

TLDR:
Misfire that presented under high load or dropped load situations was caused by a faulty alternator.

 

Is that +8LTFT at idle?
One othet easy thing is to clean the MAF and clear the ESS profile (press brake 20times with key in 'on').

If you change the rotor 2 coils to rotor 1, does the misfire also move to rotor 1?

 

Sorry for going MIA. I'm working on finishing my Master's so time is hard ot come by atm.

I cleaned the MAF when I put everything back together and I believe once since then. I also do the 20 stomp after every change I make.

The +8 LFT is erroneous. I must've remembered wrong. I've been monitoring it this week and it has ranged from 3.9-5.4 at idle depending on the day.

The coil switching is an excellent idea. And will be next on the hitlist. As soon as I get an opportunity I'm going to take off the UIM and check my handiwork under there, and I'll switch the coils while I have the accordion tube off.

Unfortunately, updates will probably be slow coming until I defend my thesis, but I will update as I get things done.

Thank you for the help and suggestions

 

Solved update: see main post edit