Str8lineJKing

First off, I have done my fair share of research already. But I wanted to get some confirmation as to my diagnosis. Am I right to think that if two coils are not sparking, that is the problem? Or is there something else down the line that could cause both of rotor 2 coils to go down at the same time?

Sorry for not stating at the beginning, the car is a 2007 M/T with 58,000 miles. If I fix the cars misfire problem, I can get it for a good deal. Im fairly certain the engine itself is sound, since I have troubleshot down to the ignition system.

Williard

iTrader: (18)

Str8,

First off, welcome.

Next, read the links within my SIG. The New and Potential owners thread is a must.

Okay, so i assume you have found an RX8 for sale in your area. I also assume it suffers from a misfire.

Aside from the CEL flashing, what are your symptoms?

Have you had a ROTARY SPECIFIC compression test done?

What steps have you taken to troubleshoot?

I will say if your replacing coils AT ALL, replace them all. I would also do wires and plugs while your at it.

Travis

BigCajun

iTrader: (1)

Welcome.
If 2 coils are definitely not 'sparking' (firing), then that is a definite problem.
Definitely get a rotary specific compression test before purchase.
If that is ok, then there are other things to consider.
Expect to have a bad catalytic converter also.
Be prepared to either buy a new one, ($1400), gut it, or buy a midpipe,
and replace all 4 coils, plugs, and wires.
Good luck!

Str8lineJKing

Thanks for the warm welcome and speedy reply. A little back story on the car is, a local big name Chevrolet Dealership took it in on trade for a 2015 Chevy Cruze. I have close ties with the dealership, and since the car went straight to their wholesale lot to be sold on at auction, i have the opportunity to pick it up for what they have in it. None of their mechanics will touch it. So basically i am working on it in their back lot. And in order for them to sell it to me under NC law, it must pass inspection. (we live in a world of liability)

So there i am, diagnosing the problem with hopes to rid the car of the misfire which is halting it from passing emissions inspection. The only code it has is cylinder (rotor) 2 misfire. Ive done extensive research on the forum, to include the "Start Here" Posts, and although i do not have access to a rotory specific compression tester, i feel very confident that the compression is still good. I did the induction timing light test on each of the plug wires, and after finding that there was no spark to the rear rotor, i insured that the wires were seated firmly to the coils, and also did the spark jump test by pulling the wires off the coils while the car is running, i got no visible spark. I am not allowed to move the car off the dealership property until it gets inspected.

I would also like to add that at idle, with AC off it will idle smoothly, so i think that the coils are producing a very light spark, but not enough to jump a large gap, or set off the inductive timing light. But if you run the AC or try to rev the engine, it surges and sets the CEL. Also, if you hold the RPM steady, at any RPM under 4-5K it runs smooth as butter.

Im trying to get a good deal here and retire my 1984 Pontiac Fiero from daily driver status to project status.

Str8lineJKing

To post script, I am a competent trained auto mechanic, and i have dabbled with rotarties, but do not have extensive knowledge of the cars as a whole. I am not afraid of lingo or criticism, i am just trying to get some back up knowledge from the forum.

Thanks in advance.

BigCajun

iTrader: (1)

Is the CEL flashing?
Then it's definitely a misfire, and new ignition components should fix that.
Did you pull the plugs and inspect them?
If not, do that.
Does your inspection involve a sniffer or OBD check?

Loki

iTrader: (1)

One thing you could try is flip the coils around so the current rears are firing the front rotor. See if the problem moves with the coils. Or set the faulty ones on the trailing spark plugs of each rotor, which are less important. But obviously the solution is just to replace them.

Personally I'm not aware of a condition that would cause only the rears not to fire, aside from the coils.

Just to confirm, we're talking about the rear coils only because the fronts fire fine, right?

Str8lineJKing

The CEL was flashing when i would try to rev the engine, but if i clear it and just let it idle, it does not set the CEL, unless the car kills itself. I have done nothing other than what i have stated, with the exception of performing the ESS clean and reset procedure.

My inspection is OBD only, no sniffer. But it is safety and emission inspection.

And yes, we are taking about the rear two coils, the ones attached to rotor #2.

BigCajun

iTrader: (1)

I think the flashing CEL is actually encouraging.
I would suggest changing the bad coils, and corresponding plugs.
If you are not getting a P0420 for a bad cat, that's good too.
Misfires kill cats quickly, maybe it's still good.
*edit* You can get online discount coupons from AdvanceAuto, avoid eBay coils.

Str8lineJKing

I have contacts with Oreilly Auto Parts and get hefty discounts. Im not neccesarily worried about longevity at this point, but is there anything wrong with the coils they offer?

Import Direct Brand. $35 Each

I will worry more about longevity and reliability once i know the car passes inspection and i purchase it.

BigCajun

iTrader: (1)

That sounds about right for aftermarket coils.
I don't remember the 1st set I bought, but that sounds like the brand, and around that price.
I replaced them with a BHR kit with about 15k on them.

Str8lineJKing

As long as everything goes as planned, after purchasing the car i would look into the Coil On Plug setup i have seen as it eliminates a point of failure in the ignition system. (wires) But if i didnt do that it would definitely be a BHR kit as i have heard so much good about them.

BigCajun

iTrader: (1)

The OEM style coils are fine if you don't mind changing them every 30k or so.
I wouldn't worry about upgrading for a while.
Once you eliminate the misfire, the cat would be the next weak point.
Mine went bad with less than 20k from a bad original coil, which were crap.
I got a BHR midpipe, and a cheap $185 Walker direct fit cat just to pass the OBD test, luckily every 2 years here.

Str8lineJKing

Thanks for the help, ill pick up some coils over the weekend and ill have access to the car again on monday. Hopefully solve the issue. if i were to gut the cat, will that cause a CEL? Ive known some late model cars to not set a light but i know of some that do.

Same question applies to installing a midpipe, does that set a CEL?

BigCajun

iTrader: (1)

Yes, the P0420 catalytic converter below threshold efficiency code.
It's why I bought the cheap cat to install a couple of weeks before inspection.
If it's still good, you could do the same with the OEM cat.
You would need to mask it with an Accessport or similar device otherwise.
I clear the occasional CEL with the Torque app for Android, $5 for the app, and around $30 for the Bluetooth OBD dongle.

Str8lineJKing

All good to hear, i already have an OBD Dongle, along with Torque and A PC based scan tool made specifically for Ford Lincoln Mercury and Mazda. It does function tests much like the factory scan tools do.

I would ask what the Accessport is, but i will utilize the search function as so i do not get shunned for asking questions i can find out on my own.

Again, thanks for the help, for tonight, its bed time.

Colon Terminus

Accessport = reprogram your ECU. Use care with that much power.

Str8lineJKing

Swapped the coils, turned the key over and she fired right up. No more misfires. Now just waiting for it to get inspected and it'll be mine.

BigCajun

iTrader: (1)

That's good to hear.
Hopefully your cat's still good.
Good luck!

Loki

iTrader: (1)

Congrats!
Based on this forum, 90% of the time something is wrong with an RX8, it comes down to coils.

Suggest that you let it get nice and warm (until the fans come on), then shut it down and start it up again and see if it doesn't have trouble starting. Juuuust in case, before you take ownership.

Gravey

iTrader: (3)

Congrats! Welcome to the Club! ^Trying to hot start it could help to see if compression is down, but there really is no substitute for the actual test. It's too bad you can't get one done before buying it.


Oh and.... PICS!!!!!!!!!! where are they?!?!?

Str8lineJKing

I sat with it for a couple hours today. Running it. Turning off and on. Eveb after running for over an hour it started right up like it was cold. Revving it out and driving around the lot. Feels good. And ill post pictures when I learn how. Its a base model dark blue. Has some cosmetic flaws, but hey, the price is right.

Gravey

iTrader: (3)

^Free?!?!?! That's awesome!!!

Str8lineJKing

Not free, but probably less than half of what it is worth.

BigCajun

iTrader: (1)

Did you get it inspected yet?