How do I prevent my car from flooding?

The RX-8 has proven to be a lot more susceptible to flooding than what most consumers are used to.

Flooding occurs when the car is started (cold) then shut down before the engine is warmed up. The reason for this is that the car injects more fuel into the engine when it's cold. When you shut the car down, excess fuel can remain in the engine. The next time you start it up, you'll find the engine turns over, but it can't spark. This can also lead to your spark plugs fouling.

Mazda has put out a TSB to help lower the chances of this issue taking place:



Some vehicles may experience difficulty starting (cranks no start). This may occur after driving the vehicle a short distance without engine reaching normal operating temperature. Examples: starting a vehicle and moving it to wash it, engine stall due to mis-application of clutch then restart. This commonly occurs at port facilities or dealer lots where vehicles are frequently started cold, moved for short distances and then turned off. This concern may also occur due to low cranking RPM during engine starting.

A cranks, no start condition may be caused by fuel flooding resulting in either fouled spark plugs or lower than normal compression.

What Mazda did was to recalibrate the PCM so that it injects less fuel than it did previously.

They also issued upgraded batteries (more juice) and a more powerful starter. The battery that shipped with the original RX-8's was quite weak, and the combination of excess fuel, weak battery, and weak starter meant the car would see the flooding issue far more than it otherwise might.

Preventative measures:

Even with the upgraded hardware, the RX-8 can still flood.

The BEST way to prevent your car from flooding is to drive it around till it's warmed up. This means a ~5 minute trip. If you're unable to drive for 5 minutes, Mazda recommends you rev the engine to 3,000 rpm for 10 seconds, then switch the car off. As you turn the ignition key, depress the throttle so that the excess fuel is spun out of the engine. I do not have much faith in this process however, as I have flooded after following the procedure precisely.

Here's my car being towed to the dealer:


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User Comments

is it not possible to remove the fuel pump fuse when u want to shut off the car in cold conditions??? and isn't it possible to just take the spark plugs out and drying them instead of calling the dealer??? isn't it possible to crank the engine when u want to start but before u do remove the injector cables so u wouldn't have any fuel then to put them back on again??? if im clearly an idiot and don't know anything about rotary engines u can say it : )
Who do i take action upon when this occurs, i bought my 04 rx8 of the lot this year and i had it only 2 weeks than shipped it from California to Hawaii. I got the car back 3 weeks later and than the next day it messed up due to the flooding. I know the dealership had to of moved it without it warmning up several times and i know the port moved it several times without warming it up. What should i do?
OH MY GOD I am so glad I found this page. I have had my 2005 RX8 towed to the dealership FOUR TIMES because of flooding. They've changed my battery, plugs, and new flash engine pieces. I'm just glad this is happening to others and not just my car. It's ridiculous that you cant drive them on short trips. But oh well.
What? 4 times? First. let me say I drive my RX8 all year in Michigan weather. Yea it gets very cold here. One flooding issue... then a friend of mine who had air planes with rotary engines and a Mazda mechanic both advise me on how to operate a rotary engine. Notice I said "operate a rotary engine" If you own an RX8 U are not driving a car with a piston engine. For some reason people want to operate like a normal car. A) Rev it up to 4 grand then shut it down. ( this blows out both fuel and ***OIL** left in the chamber...which is why u are flooding. Yea I said OIL! Rotary engines naturally burn oil along with the gas in the chamber.....It's due to how the engine stays lubricated. B) Stomp on it and often!! this will blow out the carbon build up in the engine Carbon build up is bad for a rotary your engine will love you if you get a little nutz on a constant basis. There is only about 30 moving parts ona rotary motor ( over 300 for a normal piston motor) its ok to man handle a rotary motor once in a while. (it will run better if you do and be less prone to stall at low RPM's during take off and less prone to flooding issue) Operating a Rotary motor is different than a piston motor on so many levels. Take oil changes for example... Oh.... and only use high octane gas. The car was engineered for High Octane gasoline...
When you say that you should rev it to 4K and then shut it down. Do you shit it down while you are at 4k or should you shut it down as you let go of the gas and it is dropping? I recently purchased a 2004 Mazda RX8 and have it had for 4 days now. So far (knock on wood) i haven't flooded it. I am pretty new to the RX8 and the rotary engine. I try to keep my rpm's high and cruise at around 3500 rpm's so i rarely ever see 6th gear though. Most shifts i try to make close to 7500-8500. Most of the time i drive to work which is 5-10 mins away, should i drive around more to get the engine warmed up? when i start the car, should i let it sit for a minute to warm up?
I've just got my car back on after hours of trying. Did every method I found. Pulling the pump fuse worked the best. Now, I'm afraid to turn it off. I'm praying this doesn't happen again since I missed work today.
you should have it in six gear to cruise it stops pulling you so less fule and there is a fuse that is brown remove that and start you car when the fuse is not in that will de flood the car ans drive for about half hour that should warm the engine up and when you go to turn the ar off put it to 4k the trn the key off when your foot syill on acelrator
Thanks for the input! I bought a 2007 RX8 from a dude selling it. Love the car!!! Thanks for the hints on how to operate it.
My 04 flooded for the first time last month. I just pulled out the fuel pump fuse and turned it over for abit then it eventually fired. Since then I've started having "hot start" problems. Any advice?
I dont think we will be buying another ever thanks mazda
I have a 2005 rx8 who i loved until 2010 when my car first had it's flooding problem, after sitting for 2 weeks from a snow storm. Well it happen 3 more times and it appears that it occurs after not starting for a couple of days. Costing me each time between 500.00 to 1400.00 (Jan 2012) to repair. In January 2012, i was given a sheet with instructions on how to start and stop the car. I was told when i start the engine revv it up 2 times as high as possible and drive it for at least 5 minutes and when you go to shut the car off you need to repeat the process of revving high 2x. Well i did that religiously (feeling like a fool) and wasting my premium gas and oil for a month.Well it stopped again, service stated the engine had low compression problems and it is back at the dealership and i have had enough! Service checked my warrenties, i collected all my repair and oil change receipts for a couple of years and submitted it to the manufacturer and they agreed to place the engine. Waiting for the new engine to arrive at the dealer on Monday. I was so very happy they honored the warrenty on the engine. Wish me luck.
Ride it like you stole it, DONT shut it off without letting it warm for instance, my mom recently flooded my engine because i was sleeping, although i was pissed, i told her if NEEED BE, drive it around the neighborhood. And redline it atleast once a day, Its made for it,.
My 2005 RX-8 the Engine light keeps coming on no Idea why replaced th 02 Sensors both of them . My wife drove it and never reved the Engine before shutting down will this cause a issue
i have a 2005 shinka editon rx8...i bought it about 2 years ago at a dealership with about 26,000 on it...i was new to thw whole rotary engine but it facisnated me and i thought it might be a fun car. i had a few flooding issues and then my battery took a shit bc the car sat for so long. you shouldnt shut the car of before it reaches proper operating temperature and also is a rotary engine so you should romp on it. its comparible to your average 250cc 2 stroke dirtbike they both have a power band. on the rx8 its about 4250 rmps...its no grandma car and definantly a gorgeous looking vehicle. i have been driving the car now constantly and am up to about 45,000 miles and runs beautiful...if you have any questions let me know
hey guys i have a mazda rx7 twin turbo, i did the exhaust then drove 2 work, when i left work on my way home it just back fired then had a miss sound then died,i towed it home. so the next morning i bought new plugs and tried 2 start it, it was over fueling heavy,smoking fuel heavy,didnt want 2 start, so i sent it in they did the whole motor over, they tried 2 start it but wont rev up and is over fueling heavy,i cant understand it was always good untill i did the first pipe. plz help guys.thanx DEAN.
Hey I purchased my mazda rx8 03 2 months ago and it has already flooded what needs to be replaced and how much can it cost up to?
(2004 Blue RX-8 GT 6spd)You should let the car warm up until its idleing at 1k rmp then don't hit redline until it is completely warmed up. I'm not sure about how to shut it down, I let it idle for about 15 secounds then shut the car off. Then again my car just left today for the dealer on the back of a truck due to I think egine problems. It's covered under warranty until November 2012 :-) YaY for that!!!
I have an 04 and despite knowing the trick I personally do 3k and close throttle before switching off have managed to flood it twice , so whilst tinkering I find that both ..... Both! Trailing plug coils have failed , this in my opinion greatly increases the chance of flooding , and no I haven't noticed the coils where knackered as it starts and drives fine. I will be changing them soon and will try and flood it after and see just how easy it is ... To get it going after flooding I crank with my foot right down for a few seconds then close the throttle and keep cranking ... It will start if your going over 20-30 sec stop and let the starter cool but it will go , keep cranking even when it fires until its actually running then get on the throttle up to 3k ish for 10 sec and obviously Warm it up before stopping it
i usually let my car warm up till the temp gauge is at the C. Keep revs below 4k till you get the engine at operating temperature. There is no need to have most shifts at 7500-8500. that seems like overkill for basic shifting. Try to shift lower at about 3-k rpms on a regular to save gas. I let it cruise in gear at about 2-2.5k rpms while i drive and i get decent gas mileage from it. try to use that 6th gear more often. i have been driving my rx8 for 3 years all winter long with 0 flooding issues. Rotary engines are reliable and fun as hell if you can take care of one.
Just bought a 87' rx7 with a rebuild engine, having flooding problems thinking of replacing fuel injectors trying to find the problem any advice

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