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.