roxybaby

Ok, been reading on this site on ignition system problems, and I believe I have one too. I'll describe what has happened, and those of you that have been through similar, or are well versed in the car, tell me if you think my reasoning is right.

My RX is a 2005 Shinka Edition, stock engine & exhaust. Bought the car summer of '07 with about 24k miles. Did my own regular oil changes, then had a dealer service done about 40k, they changed air filter and did a few service bulletins, said all was ok and up to snuff. Probably around 55k or so, I noticed the car seemed to have lost a bit of power, but it still ran fine and no ck engine light, so I thought it was me. Around 60k I replaced the sparkplugs and wires, using the Mazda stuff. One of the old sparkplug & wires was especially dirty, figured that plug was fouled. But the power did not improve. Around 70k I started to get rough starts....I'd have to crank it for a few seconds for it to fire up each time. Around the same time, it started to fall on it's face on takeoff from a stop sometimes. I have been meaning to get it to the Mazda dealer for another full service, but work and other things have kept me from getting there.

Well, I'm just over 80k now, and the other night, after leaving work, it started losing power while driving, check engine light would flash, power would come back, then drop...etc. Like it was dropping a cylinder (in this case, a rotor). If I stopped at a light, it would try to stall out. Babied it until just about home, could barely keep it running, and smoke starts pouring out everywhere, thought the car was on fire. Underneath the converter and exhaust were red hot. After allowing everything to cool down, car will start and run, but seems to keep dropping a rotor intermittently. Check engine light is on solid now, I assume the oxygen sensors are melted.

My thought is, that I have some ignition coils bad. Maybe only one was bad when I started noticing the loss of power....then maybe a second when I started getting the hard starts and falling on it's face...but if they were on opposite rotors, the engine would still run on one consistent spark in each rotor, and the bad ones would still fire sometimes. Now perhaps I've started to lose a 3rd coil, so on some revolutions one entire rotor is getting no spark at all, leaving the other rotor to try to keep the engine running on only one consistent spark itself, and one intermittent spark. And when that other one rotor is getting no spark, it's dumping raw fuel into the converter, which caused the fire/smoking and the red hot exhaust.

Does this make sense to you guys? What are your thoughts? I've just ordered a set of new coils, plugs & wires to give this a shot. I hope my baby Roxy is not in worse shape than I think.

Brettus

iTrader: (2)

could be a clogged cat - so get that checked then also get compression checked and put those parts in

Easy_E1

iTrader: (2)

You know you answered your question with the correct answers. Just add a Cat/MP in the deal and you might be OK. Wouldn't worry so much about the o2 sensors. More than likely intact.

TeamRX8

iTrader: (25)

why are you ordering parts without first determining that the ones you are replacing are bad?

Brettus

iTrader: (2)

/\ 80k miles so worth doing either way ...

Mazurfer

Too bad you waited past 80k miles to do something about it.
Now you are out of the 80k mile CAT warranty. It would have been free if you hadn't waited to address the apparent sluggishness.
I for one still believe bad coils and/or spark let more gas into the CAT where it ignites and eats up the honeycomb........and then you get clogged.

paulmasoner

iTrader: (1)

coils. cat is gone, hope it hasnt taken the motor with it.

roxybaby

Thanks for the comments so far, appreciate you all.

I figured it wouldn't hurt to replace the coils anyway with the mileage on the car, and the amount of problems people have had with them. Sounds like at 80k, I got a lot more out of them than many have. If my wires and plugs arent ruined, then I'll have a spare set for the next replacement. I hope to keep the car a long time yet....still paying on it for about 2.5yrs, lol. I don't think the cat was clogged initially, because when both rotors were firing I did not have a bogging out issue. Although now that all that fuel burned up in there, I will most likely have to either gut it, replace it, or install an aftermarket exhaust. RotaryFX has 2 different cat replacement pipes, anyone have experience with those?

REDRX3RX8

Ordering coils for this car to fix any performance issue is first line of defense.

Fixing anything from people to cars involves mostly logic, comparing symptoms of problem to other peoples solutions.

smokedRX8

same exact situation happened to me no more than a month ago. Coils went bad, dumped fuel into the system, burned up my cat. Your situation sounds literally identical to mine, except I had changed my coils on time. Just change them every 20k or so. only $100 for all of them. Easy work. Could've saved me $1500.

Mazurfer

^...............If you're going to stay with OEM coils...................it's just a plain, simple, smart idea.

Yeah, there are some folks that get 40k, 60k, maybe even 80k out of a set of OEM coils, but I wouldn't try it as it's just not worth the risk. That................or I'd have a set in the garage and at the very first indication of anything...........I'd be all over them!

roxybaby

Update: got the coils swapped out last nite, and the car now runs better than it has in a loooong time. Doesn't seem to be any further damage done, other than the cat is likely burned up, and my ck engine light is on solid. Anyone know if places like AutoZone can hookup to it and clear the light?

WingleBeast

if your cat it melted it is robbing you power and putting a huge strain on the motor! stop now! dont just clear the light, fix the problem or you will see your vacumme and power go to hell

Mazurfer

Yeah, get the code read please and let us know what the code is.
We can help you clear it later(but not now!) we need to see what the code is and we need it to stay there for the time being.
Don't let autozone clear it, just read it and write down exactly what the code(s) are .
We'll let ya know when and how to clear it.