mgalata1

Our 8 was indeed "flooded". The Mazda 24hr assist number was great except for the fact that the first tow truck they sent was not a flat bed or roller dolly type. The Owner's Manual even says not to tow with either axle in the air--It's either both or a flatbed.

After a morning and half the afternoon in the shop, the service manager confirmed it had flooded. The documented remedy--Replace the plugs and reset the computer(clear the flood code).

Thanks for the tip Rotarygod, but it's an automatic.

What I can relate from this experience is that when the 8 floods you don't get a warning...like a check engine light or a rough idle first. You'll know it though, because it will crank, but you can feel that there's no cranking torgue--Like the starter is just free spinning...

rotarygod

Unfortunately the autos as you have found out are hard to unflood. I still think the best remedy is to delay the onset of fuel when the starter engages and to get a starter that spins the engine over faster.

waldo

Mine flooded tonite. I followed the instructions in the manual to no avail. I read the post on pulling the fuse for the fuel pump. That worked on the third try. The last try is was pulling the fuel on its own; it was running when I put the fuse back. Thanks to everyone who has helped out in this thread!

rotarygod

That's how I start my 1st gen RX-7 almost every time!

wifedrivenRX8

My wife had to get my rx8 towed out of my garage on monday and that makes me mad being in iraq and can't talk to the service manager. My wife reports that they said there is a lot of them flooding and that the sales person is suppost to tell you when it is cold that you need to warm up the car fully befor turning it off.

LUCKY19

My car was flat bedded to the dealer yesterday because my car only warmed up for 4 minutes. I find myself racing towards garage guys and valet parkers when they deliver my car, yelling, "don't turn it off!" my dealer says that if the car is not warmed up to operational termperature - straight up on the temp guage, the car can flood.
In addition, does anyone else find the nav system wrong way too often, and that the heated seats switch, and the nav control switch are located so that your arm is always accidentally hitting those switches on a six speed?
This car frightens me every time i go to start it.

msrecant

I understand your feeling and I agree that the situation is just not right! I have owned the car since July, I have never been flooded, but I still breath a sigh of relief every time the engine catches. You just never know when your number is up.

The warning about "short trips" in the "Quick Tips" only talks about "improved engine life", nothing about immediately disabling the vehicle. Also, to me flooding is not the real issue. The problem is that there is no way to fix it short of a trip to the dealer (or a 15 mph tow behind an SUV).

I can't believe that the top engineers who gave us this award winning engine, didn't know about this problem or that they couldn't have provided a solution, even if they had to install some kludge like the old sub-zero starter fluid button/injector that came with early Mazda rotary engines.

2_Rotors

I have one question. what is it that causes it to flood. I know that i floods when it is cold but why.

X-SIN-X

http://auto.howstuffworks.com/rotary-engine4.htm

Ineractive animation of how the wankel operates.

Okay, My RX8 does not start and it is flooded. What do I do to get it started?

rotarygod

The amount of fuel needed by the engine is inversely proportional to engine temperature. With a cold engine, a huge amount of fuel is required just to get enough to vaporize, so it can burn. However vaporization at starting rpms is almost a joke since there is not enough turbulence at only a few hundred rpms to vaporize the fuel effectively. This isn't as much of a problem at higher rpms or as the engine warms up. The hotter the engine gets, the easier vaporization becomes, and the less fuel is required. Vaporization is also why it is typically much harder to start a carburated car in cold weather than it is a fuel injected car. To combat this most carbs have some sort of way to heat the carb through a coolant passage running through them. This allows the fuel to heat up faster after the vehicle is started but is counter productive once the engine has reached operating temperature since the last thing we need for true performance is something heating up our intake charge such as a hot coolant passage through the carb. Most fuel injected throttle bodies also have a coolant passage designed to help heat the air sooner as in the carbs. I have mine disconnected on my RX-7's and on my Honda and have noticed no ill effects. To combat our fuel atomization/warmup problems even more with the rotary, we also have our air fuel mixture traveling a long distnce throughout the engine before it ever gets to the spark plugs to be lighted. This leaves alot of surface area that the fuel can stick to and therefore not be atomized but rather a buildup. This huge amount of surface area also takes longer to heat up since the exhaust gasses are primarily concentrated on the opposite side of the engine. A piston engine has less surface area inside the cylinder and the fuel in essence stays near the plugs at all times. when the engine fires and the exhaust is expelled out of the exhaust valve(s), the heat of combustion is still present on the valves and in the head which enables the combustion chamber to reach higher temperatures internally over a shorter amount of time. We have so many things working against us as far as starting is concerned within the rotary. In some ways it is amazing that it starts at all.

A couple of fixes for the starting issues is to either find a way to spin the engine faster, warm the inside of the combustion chamber up faster, or increase fuel vaporization. As compared to the earlier 13B engines the increased atomization is already done with this engine. The '84-'85 GSL-SE 1st gen RX-7's had only 2 fuel injectors that were 680cc. The '89-'91 n/a 2nd gen RX-7 had 4-460cc injectors. The '87-'91 Turbo II RX-7 had 4-550cc injectors. The 3rd gen RX-7 had 2-550cc and 2-850cc injectors. The RX-8 has 6-330cc injectors (I think? It's 3??cc nevertheless). All of these cars only use 2 fuel injectors to start the car while the others come in later. A smaller injector can atomize fuel into smaller particles since they spray the fuel in a finer mist at a lower flow level than their larger counterparts. As we can see from above, the RX-8 has the smallest single pair of any of the previous fuel injected rotaries and therefore a finer mist is available at lower rpms. While a smaller injector is limited ultimately in total flow ability, the RX-8 has 6 unlike the max of 4 in any previous rotary. The other 2 things would be to warm up the engine prior to starting or spin it faster. Spinning it faster would be easy and not very complicated thing to do. A larger high torque starter motor with a different gearing would do the trick. It wouldn't even take much more speed. The only way to heat up the combustion chamber would get quite complicated since it would have to be done electrically. A diesel engine needs the glow plugs heated up before the engine is started. While a glow plug is always hot and a spark plug is not, the engine starts better with more fire in it. A diesel will still start without allowing the glow plugs to heat up. It just isn't good for them and it may be harder to do. In a rotary application we could apply some sort of temporary electric heating jacket around the fuel lines to slightly heat up the fuel. Nothing in direct contact with it though. We don't need a bomb.

There is one more option though and this is probably the most practical way to do it since fuel injection makes this option very simple. There is an ecu mod for the 2nd generation RX-7 that is made by an aftermarket company. Mazda, I hope you guys are reading this! It's pathetic that you couldn't do this on your own!One of the things that this ecu mod does is to create a means that makes it easy to unflood the car. When the throttle is pressed all the way to the floor during startup, fuel flow is interrupted until you back off the throttle. You need only to floor it for a second or two with the engine cranking and then let go of the pedal. It starts up every time. Edit: I was just informed that the RX-8 already does this! Maybe minus the start up every time part. I would use this procedure every time I started the car.

Basically the 2 easiest things to do are to spin the engine faster at startup or delay the onset of fuel flow for a second or two. Viola, no more flooding issues what so ever!

rx8cited

hi X-SIN-X,

Sorry to hear this. Did it get flooded because you had started the car and not let it warm up for at least 5 minites? Just curious.

Anyway, have you tried the following procedure from the Owner's Manual page 7-20:

"If the engine fails to start, it may be
flooded (excessive fuel in the engine).
Follow this procedure:
1. Depress the accelerator all the way and
hold it there.
2. Turn the ignition switch to the START
position and hold it there—for up to
10 seconds. If the engine starts,
release the key and accelerator
immediately because the engine will
suddenly rev up.
3. If the engine fails to start, crank it
without using the accelerator—for up
to 10 seconds."

Let us know what happened.

good luck,
rx8cited

PS: There are threads on this subject, so you may want to try searching for them.

rotarygod

I need to go back and edit my last response. I was not aware that the RX-8 already had the unflood proceedure which I suggested. That's what I get for only having RX-7's. I would be inclined to do that procedure every time I started the car just to be safe.

jtimbck2

That's OK -- thanks very much for all the information! As a first-time rotary owner, it was very enlightening!

XeRo

yup...flooded mine..ONCE...tired after working on trying to complete my workshop and had to pull the 8 out of the garage for space to make the trusses and about 4 hrs later went to pull the 8 back into the garage and it was flooded..started for a brief second, shuttered then died,...*lump in the throat*....after about 10 minutes of off and on again starting without giving gas it cranked, sputtered, ran real rough, pulled it onto the street, got up to good warm up temp took it down the new development street...LET HER LOOSE>....haven't flooded again....don't plan to either....scary...

8_wannabe

Aren't we going a little over the top here? I admit, if my car had flooded I would be more unhappy but the vast majority of '8s haven't flooded (there are polls on this forum.) Furthermore, I don't know of anyone who has flooded more than once, and if there is they would be in an infinitessimal minority. This doesn't mean it isn't a problem if your car is flooded at the moment; clearly that sux. What it means is, its' not some monstrous systemic problem.

If you're bumping nav/seat warmer controls you have adopted a lazy arm position in shifting. Keep your fingers lightly on the shift ****, elbow up, not resting on the center divider.

I have used my nav system probably 150 times. Of those, twice it came up really "dumb" meaning I was off the road and going in the wrong direction. The off the road part is endemic to satellite transmission problems, atmospherics affecting time-of-receipt of signal. It is very sensitive to tiny errors. Not a problem with the car, it has to do with electromagetic transmission theory and not much you can do about it. Going the wrong direction was puzzling; may be the same thing if the car gets directional info from the satelllite, otherwise it's a gyro problem. In general, as you drive the GPS will ultimately figure out where you are and the error vanishes in a minute or two. If you don't know which direction to drive, turn off the system then back on, and it oughta be ok. Not a great answer, but I have less than a 2 percent error rate which I think is pretty good. I saw the same behavior on a 2000 BMW, so I think its just state-of-the-art on consumer GPS.

If you are frightened about driving this car, then you are probably frightened of frequenting public places in case a terrorist hits, or frightened of shaking hands for fear of the flu. Just relax a little and enjoy life. Unlike other hazards of life, you can reduce the likelihood of flooding to almost zero percent with slight modification of your behavior.

Habeeb

It looks like only 16% of people that replied have had the flooding problem. That's not terrible, although it's one problem with the engine that most would gladly live without. *Breathing a sigh of relief* each time the car starts isn't great for building long term customer loyalty. ..Now.. all these cars probably have less then 10k on them. How will this situation play when there is 40k, some wear on the engine and just maybe the battery, plugs and general tune of the motor isn't at optimum? Most old rotary folks will remember the first cold snap with the fuel injected cars. Bring them in *on the hook* flooded... The cure for the 86 and later cars was to pull the check valve from the fuel pump. That way instead of the leaky injectors allowing all that fuel to the engine it would drain back into the tank. Since the Renesis is new, and probably doesn't have leaky injectors... yet, would a valve to dump the fuel under pressure back into the tank even be a solution? I haven't been able to get to a workshop manual yet. Anyone know if the 250rpm cranking speed from the 3rd. generation cars has carried over to the 8? Always thought that was a contributer to the flooding problem... just my 2 cent ramblings..

Silver7

I agree with LUCKY19. I am not willing to tolerate the flooding problems associated with the RX8. We are not talking about something minor here. We are talking about something that could potentially get someone stranded. If this car floods again then I really doubt that I will keep it. My girlfriend is the primary driver of the RX8 and I just can't risk her getting stranded somewhere. We bought this car so she would have something reliable and fun to drive. If it's not reliable then it will have to go!

rotarygod

Looks like you'll be selling your car then. Sorry man. Have you ever owned a rotary before? Just curious. It happens to every rotary at some time or another.

Silver7

No, I've never owned a rotary before I have made several posts in this forum comparing this car to my previous rotary powered vehicle (93 RX7). Back when my FD was my daily driver (1998-2002) I never once doubted that my car was going to start. I also never worried that if I stalled it might not start back up. I never worried about flooding the car during cold shut downs. My gas mileage was better than the rx8's gas mileage by more than a few miles per gallon and the car was significantly more powerful than the rx8. I'm not saying that the FD didn't have it's problems, but I was never worried about whether it was going to get my from point A to point B. Mazda took a great car (the RX7) and took out the thing that made the car unreliable (complex twin turbo system). Then they went ahead and improved on the engine design (two oil injectors per rotor, stronger redesigned 2 piece apex seals, variable intake manifold, side exhaust ports, which were supposed to improve emmssions and fuel mileage and probably some other things I am not aware of). This car has all the ingredients to be the most reliable rotary ever, and it quite possibly may be once they get all these kinks ironed out. Bottom line is...
1)my rx8 has already flooded once
2)it occasionally has a hard time starting up, almost like it's on the verge of flooding but the engine catches before it has a chance to.
3)gas mileage (with my GF driving) has been rock solid at 16 MPG. If I remember correctly, mazda claimed 18-24.

I love rotary engines and have even built a handful of them, but I'd be lying if I didn't say I was a little disappointed in the RX8.

Positron

This is my third rotary (two previous 7s) and I have never had the flooding problem. I am aware of the issue of moving the car when it is very cold and shutting it off after only w or 3 minutes and I try to avoid the situation if at all possible. But the times when it has happened I have never had a problem re-starting the car. I'm not sure why some (maybe only a small percentage of rotary engines) have this problem. But it certainly isn't a universal problem to all cars.

(On my first RX7 I had to use gas line antifreeze in very cold weather or ice would build up in the gas filter and then the car wouldn't start, but that's another story.)

So there's my two cents on flooding.

rotarygod

I may have figured it out but I'm not quite sure yet. Here is a possible explanation that I just posted. After some experimentation we'll see.

https://www.rx8club.com/showthread.p...threadid=17108

rotarygod

FWIW: I was not trying to be an *** to that guy but he did say: "If this car floods again, then I really doubt that I will keep it." It WILL flood again someday and by that statement it looks like it will get sold. The RX-7s were admittedly easier to start than the RX-8 with less flooding isses but they still do flood from time to time. I am starting to suspect that it has everything to do with the ignition system and the short plug firing time and weird idle ignition timing that I posted in the above link. The igniton system is completely different by design and operation than any previous rotary and runs in a format that we have not seen in use until now.

8_wannabe

Silver, I hear what you're saying and can appreciate you wanting reliable transportation for your gf. However, you also posted:

"I have owned an FD for over 5 years now and have never had the flooding problems that these rx8s are experiencing."

The FD was also known for flooding. I only know that because it has been stated in this forum about a zillion times, this is a problem of rotaries in general. Not a huge problem, except when it happens and then it is huge at the time.

The main difference between the FD and Renesis, in terms of flooding, is that the odds finally caught up to you. Surely you must have known your fellow FD owners were experiencing flooding, but the odds remained in your favor. Now that it happened, suddenly your whole perspective changes. I tend to view things statistically; much of what we encounter in life can be described by a bell curve. Most of us will never experience flooding (statistically speaking.) Many fewer will experience it repeatedly; picture the trailing tail of the bell curve. Who here has had it twice?

All this theortical stuff doesn't take the emotion out of it, especially when you are trying to take care of someone close to you. But if you look at it dispassionately, the problem overall is not that great, and if you follow basic rules then even less so. If you were to measure the overall reliability of the '8 from all causes as opposed to that of other cars from all causes, is the '8 any less reliable? I dunno, and because I dunno then moving from the '8 to another car may provide the appearance of progress while providing no progress at all. This is basic organizational theory: "When in doubt, reorganize."

On a final note, she must be one heck of a gf for you to buy her an '8. All I can say is, if you ever break up I'll be ur gf if you buy me an '8.

Silver7

8_wannabe - I understand what you are saying (don't agree 100%) and my intention isn't to get rid of the 8. I think some people just aren't willing to accept that their brand new $30K car has some serious issues IMO. I am using this forum to express my honest opinions and to vent my frustrations with the 8. I feel partly responsible since I steered us in the direction of the 8 and now that it is having problems I feel that I have to justify why we bought the car.

8_wannabe

Well, along the lines of my earlier comment, the main difference between you and me is that your car has flooded and mine hasn't. If it did, maybe I'd be singing a different tune. But I had no prior knowledge of the rotary flooding issue; I came into this as a total novice.