balletsushigirl

is anyone else noticing how only certain 8's are having repeated trouble with flooding in the engine while other 8's are experiencing poor gas mileage?

what i mean is : i've never had a flooding issue (even when an attendant shut my engine down completely cold), but my mileage sucks -- whether or not i drive to mazda recommendations or not (i.e., shifting according to the specs in the manual).

maybe i'm stretching here, but perhaps there were different production sites in japan, and certain sites put out cars with particular problems and not others.

is this even possible????
if possible, might it be probable???

just a thought --

BSG

zoom44

no all rx8's are built in the same plant. the engines are all hand assemble by like 10 people. however there could be variations in engines based on which one of those 10 or so built yours.

RX-8 friend

As far as I know there is only one plant where the cars are assembled. It was shown to the media just when production was starting about a year ago. We haven't seen differences in the ECU program except Japan vs everybody else (but we have a very small sample so far). It's possible there is a bad batch of sensors or even wiring harness'. I think it's too early to tell yet, and hopefully, Mazda will be recording all reported problems vs VINs and will get on top of any correlations.

MEGAREDS

The flooding issue doesn't seem to be same sort of mystery the fuel economy issue has been. I don't think anyone has convincingly explained why the RX-8 is producing sub-standard mileage - whether compared to initial RENESIS expectations (34mpg) or EPA estimates (18-24mpg).

The flooding issue is different. If the car is shut down cold there is a possibility that the car will flood - end of story. The flooding reports have almost all been because the car was shut down too early in the warm-up cycle. Some people are reporting the ability to shut down cold without a problem, but I don't think anyone has been willing to go outside and test their luck every day.

By the way, there are new plugs available for the car and the rumour is that Mazda is hoping they will aleviate the flooding issue - i.e., make it less likely that the car will be unable to start. See the latest TSB "Parts Flash"

pauleta

Are the new plugs a guaranteed fix? Are they only being replaced on those cars that have had flooding problems?

zoom44

well to quote myself:


hardly anyone reponding to that idea of mine. i had hoped it would spark a discussion of some sort, to see if my arguement there had any validity. "why quote my post concerning fuel economy?" you ask? because i think the fuel economy, flooding issue and HP reduction all have to do with that tune they did to bring the car into cat longevity compliance. but without knowing the original tune parameters or having good feed back from JDM car owners we have nothing to work with. we need someone to get the original tune somehow.

93rdcurrent

I definately agree with Zoom44. I somehow managed to miss that original post or I would have commented. If the flooding issue is as it seems a tuning issue then we would have a huge complaint to file with Mazda. We could also argue our point and maybe get high temp cats through our warranties. There are a lot of possibilities and I think that it is a serious issue we need to get to the bottom of.

Now how do we do it? I know some well to do corporate attorneys that could help with legal issues (my wife graduated from Gonzaga University and her uncle sits on the board of regents for the law dept.). I would like it if Canzoomer were able to profit from his hard work through this as well.

zoom44

oh and one more thing. since most of the flooding appears to happen the first time someone starts their car on a particular day people think it is a problem when starting that causes the flood. what causes the flood is too much unburnt fuel in the combustion chamber combined with(perhaps) rotarygod's perceived igniton setup problems. i think that perhaps it is fuel left unburned from the previous trip in the combustion chamber with new fuel dumped on top in the cold engine when you try to start it next. so i think that a leaner overall fuel map would help lower the amount of fuel left in the engine after shutdown. i wanted to point this out because i had not read anyone stating it that way before. i fyou had sorry i missed your post

btw i am by no means an engine mechanic or a rotary god. i am merely a person who tries to think around problems and puzzles and come at them from different angles until i find a solution that works logically and easily. so you wont get alot of the equations and math and specifics from me. you'll have to get that from people like canzoomer, wakeech, buger and rotarygod

RX-8 friend

It's a plausible theory. Note that the car is only "rich" above 6000 RPM. It's quite lean below that. I don't think we have checked the air/fuel during warmup. Perhaps that is way too rich.

Personally, I think the coils are too small (weak spark) to "burn off" plug fouling. They are really very small (have a look under the intake rubber leading to the MAF - just where the intake exits the air box. Look way down and you'll see four modules mounted to a metal bracket with one ignition wire each leading to the plugs on the drivers side of the engine).

I believe someone has already tried replacing them with an aftermarket "super ignition" and found no performance benefit, but they may not have noticed if it helps here.

It's most likely a combination of several factors. Rotaries have always been subject to flooding, it just hasn't been this big a problem (number of reported incidents on new cars) in the past.

93rdcurrent

After reading Canzoomer's post over in the tuning area I think that Mazda had the ECU Air/Fuel mixture mapped out at about 10:1 for WOT and it was like 13:2 at normal driving conditions. I believe that Canzoomer's upgrade puts it to more like a 13:2 at WOT and 14:6 at normal driving. That is a substantial difference at WOT. Like what 25%.

My figures may not be perfect since I am going off of memory. But it should be close. If cold start has the mixture running rich I am guessing that we would be close to the 10:1 and with a problem relating to spark at ignition under those conditions may lead to a serious flooding issue. This is my guess but as I have stated before I still think that running a car rich to save the cat is most certainly not the answer to helping our enviromental problems and it is also not responsible on the part of Mazda engineering.

Give us back our hp and gas milage, screw the cats!!!

MEGAREDS

No, and that is closely related to one of my complaints right now with the flooding "issue." Mazda won't even acknowledge that RX-8's flood due to the failure to warm up the engine. As far as I can see, it's not to be found in any Mazda literature. The manual describes a procedure to try to start a flooded engine, but doesn't give a clue as to why the car might flood. The Quick Tips brochure says that a short-move procedure "should" be followed when jockying the car around, but then implies this is so only because "Warming up engine improves engine life." I think their marketing and legal people just refuse to allow them to make the connection out of fear of consumer backlash and lawsuits, respectively.

So far, they've repaired cars under warranty, but don't seem to be saying that this policy will continue... and that is what really concerns me.