Engine Misfiring
 

Just curious if anyone else has experienced this. Driving onto the highway I hit about 8k RPMs and the car started to "buck" and it felt like it had lost power. I shifted into 3rd and the problem went away though the engine light blinked several times. At the next chance I dropped to 2nd gear and hit 8g again, and once again the same thing, cept this time the engine light blinked and then stayed on.

I immediately called the dealership and brought it in. When the mechanics were done they said the compter said the engine had mis fired twice so they reset the computer. I asked what caused the problem and they didnt have a clue, they said " well dont hit 8,00 RPMs then". I wasnt happy with the answer or that my new car was having engine problems but I left it at that.

Now again today in 3rd i got the car up to 8k and once again I noticed the powerloss and the engine light flashing. After shifting and waiting a few mintes and gunned it again. This time nothing and the car ran fine all the way to 9500. In between these 2 instances I have hammered on the car many times and it hasnt happened. Im more curious if anyone else has had this happen or if anyone might have a clue whats causing it. Personally I feel like going to the dealership and raising hell, as after buying a brand new car and having a problem the mechanics there are happy to just reset the comp. and read to me what the computer says and not actually put any effort into finding out why it happened.

You might need new sparkplugs

I'm not sure whether this will make you feel better or not, but i also got a "random misfire" under semi-hard acceleration which caused the CEL to come on. Dealer didn't do anything except clear the error, which I wasn't happy about. I believe others have also experienced this.

I don't have a lot of confidence in my current dealer. I don't drive my RX-8 in the winter very much but when I start driving it again, I'm going to pursue it further with Mazda directly. The previous suggestion about new spark plugs (that are hotter) sounds like a reasonable solution but I'm not sure if my dealer will do it.

I have an automatic and have experienced some bucking and loss of power......it only seemed to happen when the car was not fully warmed up....never experienced it when fully warm. Dealer checked it out and said engine was fine....could be moisture and/or just cold engine.

How many miles are on your car? If it is under a thousand miles, then it could be that the engine is not broken in, and it would be best if you broke the car in before revving it up.

What kind of gas are you using? Non-premium gas can cause misfiring.

How warm was the engine when you did this? Mine likes to have hit mid temp mark plus 5 mins before it is really comfortable.

The exact same thing happened to my car for the first time today. I was in a fully warmed car with 93 octane gasoline and I felt a surge and power loss at about 8000 RPMs. My check engine light was blinking for several seconds before returning to its customary on positiion (my dealer and Mazda have yet figure out how to fix my CEL which has been on for 4 months and counting). Until now I have had no problems with the car except the aforementioned light. I have driven it above 8000RPMs after the incident without problems.

Hrm- I had something like this happen last week, and thought maybe I did something. Maybe it wasn't me. As I pulled out of work, I threw it in 2nd gear and hit the gas. I normally shift to 3rd then when I hear the buzzer, but all of a sudden the car just kinda stopped accelerating, (I'd guess it was around 6-7k rpms- because I was only going about 45 by then, and I wasn't looking at the tach) like it had lost power. I thought maybe I had bounced it off the rev limiter before I looked at my speed and upshifted to 3rd. Car was fine after that. No lights or anything came on, and I haven't had it happen since then.

Weird.

It does sound like it has something to do with the rev limiter or the knock sensor to me. Both will cut back on fuel giving you the weak feeling in the power.

My demo did the same thing a couple of weeks before it started running really bad. Wouldn't rev past 4500 RPM. Turned out the O2 sensor was bad causing it to run very lean. New O2 sensor and haven't had any problems since in about 3000 miles.

No, non-premium gas does not cause misfiring. Stop spewing that trash. Dirty fuel of any grade might cause it, but it's not a function of octane level.

My UK hi power car has done this several times (and with the dealer in the car), it is going into the dealers tomorrow morning for a check and I believe new spark plugs.

It is very intermittent though! I have filled with Shell Optimax (98 RON UK) and it still does it now and again! Car only has 700 miles on the clock though, so it may need loosening up, but over on UK RX8 owners club forum there has been a lot of discussion about this and one guy's car has started doing this after 2000+ miles for the 1st time!

Wierd eh!:eek:

I'll post how I get on............

http://rx8ownersclub.co.uk/forum/

Re: Engine Misfiring .....
 

Holey crap, what kind of answer is that!?!

It's a different feeling from the rev limiter. when you hit that, the car just stops accelerating. This feels like the car has all of a sudden lost power and just up and quit.

Budaman2...did computer diagnostics point to bad O2 sensor?...or was it trial and error that found it?

I live in NH and with the weather cold, Ive always let my cars heat up before moving them at all. Even warm I let the engine warm up and oil thin before taking off, more so if i plan on being a lil foot heavy. My car was fully warmed up both times and probably 3-5 minutes into driving when it happened.

I "believe" this time i went with 89 octane gas ... Have tried 87 89 and 92 ? i think to see if I noticed any difference in performance or MPG (I havent yet).

Ive had alot of problems with the dealership before and actually complained to mazda about them when I had my miata. Getting a response of "dont go up to 8k RPMS" on a sports car is one of the most retarded responses Ive ever heard a mechanic spout out. Im planning on calling the other local mazda dealership who have been great with fixing problems ... Funny thing is when I get problems like this I dont hold it against the car or mazda for the most part ..... cars are mechanical and things will break, I can accept that. The part that pisses me off is poor service from the place I just spent 30 grand on a car at.

As for the problem .... on mine it was definately a noticeable misfire. almost like it was missing 1/2 the time. The car was tryin to go faster but was sputtering. The 1st time it does it the CEL will blink a few times and go off. If you do it again w.o turning the car off it will blink and then stay on.

Would this problem be magnified by running too rich or lean or both? Thinking about that post mentioning why Mazda richened the mixture to prolong cat life...

just found this thread and I have had a cel ever since the new m flash. My car is detonating like crazy. Also my car has a hard time starting. This will be the 3rd attemp to fix it at the dealer. They have done new plugs, new wires, and now I have no idea what they are going to do. I give them credit at the dealer they are trying to fix it. In the end I hope to get a motor. I also have alot of smoke from the tailpipes sometime aswell.

When a mechanic states something like that it's time to find a new one. I almost wish, like Bugs Bunny cartoons...you could pull out a glove, stick a brick in it and say...

'You sir, have insulted me......" SMACK!!!!!!

You should have called Mazda and tell them that a mechanic at "BLANK Mazda dealership" said I could not or should not rev the RX8 to 8,000RPM. I'd bet they GET ALL OVER that dealership. Just think if someone at MT or R&T heard a response like that...Mazda would get another BIG BLACK EYE!

Crap.. add me to the list. Yesterday I was traveling about about 60-70 in third.. hit 8000 was just about to shift and BAM.. blinky blinky CEL, car is sort of stuttering.. so I quickly upshift and the CEL goes away. Spooked, I take the next gear to 8g and same thing.. stuttering surge and blinky blinky CEL...

Oh no.. what is it??????

I got an appt to the dealer next week. I hope to God they dont tell me something stupid like that. Or heaven forbid they tell me something is mortally wrong with the engine.

What do you think engine gurus??

i think you had a misfire. maybe need new plugs? or at least the curent ones cleaned.

hmm. several things could be going on there. if you are using 87 octane it could be that the plugs are fowled. the best way to check that is with a plug socket. if the plug is brown and nasty looking. replace them and put a fuel booster/injector cleaner in the tank. if you have to use the lower grade fuel, try to buy it from a busy station. they move more product there for always have a fresh tank. the problem with the dealer is they don't have a clue how to work on or trouble shoot the wankle. try and find a specialty shop and get their opinion.

Nope, always use 92. I hope zoom is right and it's that simple. If so, that would mean no major damage eh?

On the other hand, if it's not that simple, what else could I be looking at?

PS. It's not flashing now (as in, all the time), but I bet if I performed the same manuever, I can make it flash again.

do you have the stability control? that, i think, retards the ignition if it is activated

Yes, GT model with TC/DSC... hmm it was raining while it did this.. hmmm.. but would the DSC blip CELs like that.. would seem odd.

you wouldn't think so but with they way everything is integrated and combined on this car....

True.. well, I guess I better drive like a grandma until I make it to the dealer. I will post codes if I get some. Maybe Snapon can shed some info then.

You guys one thing to keep in mind is this:
On track days I have had issues with the fuel getting to the motor, this is due to the way the fuel tank in the 8 is designed. It has a cut out section where the drive shaft goes through, this leads to a couple of problems. When driving hard and accellerating especially on straights the equalising pump ca not keep up, hence you get fuel starvation, and the car surges (basically it feels like you have hit a rev limiter, this only happens when you have less than half a tank of fuel. I have had it happen from 6000rpm on wards but once as low as 5000. I have reported it to mazda her in Aust and they commented that it was the first time they have had that reported. My car is not the ony one, at subsequent track days 4 other people I have driven with have had exactly the same issues.

Therefore, before looking for something more simister ensure yu have a full tank of gas and then try exactly the same thing again, it could be the equalisation problem within the fuel tank, if it is the same problem then report it to your dealer because I personally would love a fix for this issue.

Regards,

Gibbo.

Ignition coil faulty, maybe sparkplugs. A blocked cat will also cause this.

The symptoms are also in line with a faulty APV valve, although you don't usually get a MIL with that.

The dealer needs to do some diagnostics....

Had a pretty full tank.. less than a 1/4 down from full.

On my way home from work, I drove it hard to try to get the same CEL but it didnt happen. Hmm. Should I not push the car until I get to the dealer? Maybe I'm messing things up more.. :(

It's hard sticking to the Granny method in this car, you all should know that.. :)

Same thing happened to me 3 times now (2x with me driving, 1x when my wife was driving). I thought it was a problem with my CZ Stage 1. I even emailed Maurice about it and he had no clue. I took it to the Mazda dealership after the 1st 2x's and they couldn't find anything wrong with it. They just reflashed my ECU. It happened again a few weeks later. I called Mazda and made an appointment but then it went away. No problems since.

This is what happened:

I drove away from my house, it started sputtering...I was probably only going 25-30mph. The CEL came on. I went back home. Turned off the car and started it again. Still CEL light on. Came back later in the day and CEL light did not turn on and car ran fine. The next day my wife said it did it to her. When I checked the CEL light, it was not on. That's when I took it to the dealership.

The 3rd time, same thing happened. I turned off the car and when I came back it started fine.

I really hope we get an answer to this problem so I can enlighten the Mazda techs down here what to look for.

Well, my car is in the shop. I told the tech to drive it home for the weeekend to see if he can get the light to come on. Last time he had it (5 days) no light but after I get it back the light came on 10 minutes after leaving the dealership. I really hope this gets fixed a misfire is something pretty serious IMO. It is not good for the motor and we are like lab rats for mazda testing all these different flash programs. I for one am not taking no for an answer this time. I want a valid fix for my misfire & smoking out of the exhaust.

I had that problem after the M flash. Took it in last week and the dealer reflashed it. Runs great now. Makes smooth srtrong power in upper rpms again like it used to. I also made a future appoitment for an oil pan replacement and new plugs , all covered under warranty.

i never got the M flash, when i called to make the appointment they told me it didn't fix the problem. i never had a problem so i guess it didn't affect me anyway.

Just had misfire problem fixed
 

I thought I was losing my mind. Right after I had the SR intake installed, I noticed what I thought was misfiring above 4k RPM. This continued for a while and I had the SR exhaust installed. It may have been a coincidence but not long after as soon as I hit about 3500 RPM the car would start misfiring like crazy to the point the power almost stopped until I shifted to another gear but kept it below 4k RPM. I brought it to my Mazda dealer and they could not find what was causing problem. When they called the Mazda tech line the tech did not want to get involved because of mly aftermarket bolt ons. This lasted for about 2 weeks. I finally brought the car in again this week with the same problem. I was not enjoying driving the car at all. After 3 days, the mazda tech found that all 4 resistor packs had been burnt. He showed me the packs and you can see the burn marks. They were cool and changer all four as a warranty fix. It is like having a new car again. The only problem was when this was going on and I was not sure what was causing the problem and had the dealer remove my SR intake and replace with stock intake. I can really appreciate the car now especially with the SR exhaust which sounds great.

Ok.. Brought her into the dealer and they find a P0302.
I ask them, what is that.. they say. Oh it just means you need a reflash.

Isnt that a misfire?!?!

They dont believe me.. throw some BS.. and say the reflash should fix it.

Can any gurus out there confirm that this is the correct fix for this code? Snapon? Maniac? Isn't a misfire some serious sh1t?? Why are they treating it like its nothing? Or am I worried for nothing?

Man I hate dealing with dealership service centers. :mad:

P0302...rear rotor misfire. While the engine is running, the PCM counts the number of misfires at 200revs of the E shaft, and at 1000 revs. If the ratio exceedes a set figure, the PCM determines that a misfire that could damage the cat has occurred.

P0300 Random misfire detected Flash/ON 1 or 2 Misfire ´ (See DTC
P0300 )
P0301 Front rotor misfire detected Flash/ON 1 or 2 Misfire ´
(See DTC P0301, P0302 )
P0302 Rear rotor misfire detected Flash/ON 1 or 2 Misfire

you're already on the most current flash so what will they do beyond that? have them inspect the plugs and clean or replace.

edit: damn gomez is quick
edit 2: and tell them to check your cat. as per gomez above:)

Unfortunately (for her), my wife says the same thing..... ;)

The fact that so many of you guys in the States have these issues and no-one else seems to, leads me to believe that this may all stem back to your "K" and "L" flash issues (fouled plugs)....

Hmmm.. is a misfire a serious issue? Could I be looking at long term damage?

I'm going to drive the hell outta it, this week and see if it comes up again. They claim it was ok as they tested over 8K RPM. Didnt really like the idea of them pounding my car, but that's the only way it would pop up.

If I have to go back because it comes up again, I will definitely tell them what to look for.

That was my issue. I used to smell fumes from the car and it would buck just as you stated. When mazda looked at the codes from my car it had the P0300 like everyone is stating. They replaced the wires and now everything is fine.

Can ayone make any sense of this... it was on my work order..

Reflashed PCM to 34.8 Patch 2 & Reset the E-shaft plate.

Can that fix a misfire code? hahaha.. sorry, still paranoid.

so they did a flash of your pcm that just brings you current and has nothing in it for misfires that you didnt already have. then they did the 20 stomp on your brake pedal to clear/reset the eshaft profile. flashing can clear the code but it wont fix the issue imho. you were already on M so the flash didnt change anything. btw how you doing? havent talked to you in a long time. how are the islands this time of year?

ARRGH.. I was successful in duplicating the misfire this morning on my way to work. It seems my dealer didnt fix the problem and just did a reflash hoping it would cure it. Obviously there's something more going on. The work order did say they check the coils, so I do feel a tad better.. NOT.

Am I wrong to think misfires are SERIOUS? Just the word sounds bad. I'm not a engine guru or anything but is this common? I mean I could live with the CEL light blinking, big deal, but man it just spooks me when I turn up the juice on the engine and she starts bogging like she's outta gas or something.

ARRRRGH.. What a waste of time. Now I need to schedule in another day for them to work on it. DAMN.

Did I say I hate dealing with dealership service centers?? :mad:


zoom.. I'm doing good.. was perfect until this problem happened. haha. The islands are beautiful this time of year. Hasn't been as wet as it normally is. Its pretty cold though, if you consider 60s, low 70s cold.. heehee.

hey nut pm me your email addy. i got something for you

same thing started to happen to me AFTER THEY FIXED MY CAT.. i will drive my car hard and the CEL will start to blink...i will let off and it stops...i dotn know why its doing it either? anyone out there know whats up w/ it?

you need the code it stored when it blinked. but it could be something as simple as an eshaft sensor problem. or it might not be a misfire at all. neeed the code first.

Hmm.. does the car seems to hesitate as if it's outta gas? Kinda like stuttering?

New info.. pushed the car to 8K once more. Just had to be sure :D .. I know I should stop it.. Of course the CEL blinked.. seemed to blink longer this time... and get this.. are you ready... it remained lit. CEL is still on as I type.

Uh oh. :eek:

Looks like it's gonna stay under 3500rpm for me until my baby sees the doctor... doh! Now this is gonna be the longest week ever! :(

Its a good thing RB has a back order on exhaust. If I got it in when this happened, I'm sure the dealer would start blaming the exhaust.