Flooded RX8

Flooded RX8 – How To Start A Flooded Mazda RX8?

The Mazda RX8 is a great performance car for a relatively low cost. Rather than your conventional engine, the RX8 has a rotary engine and as you may know, rotary engines can suffer from flooding relatively easily. Once you have a  flooded RX8, it can seem impossible to start, but in the article below I will show you how to start a flooded RX8 Mazda without the huge mechanic bill. Learn everything you need to know about the Mazda RX8 engine in our guide.

RX8 engines are known to have lots of problems some won’t start, some have hot start issues and some have misfired. But most owners will come across the not starting problems.

On this occasion, the flooded RX8 engine was caused by moving the car from one location on the drive to another, without letting it warm up enough.

Some Proof That It Works

Here you can see our flooded RX8 starting using this method.

Flooded Engine Fix

What you need:

how to start a flooded Mazda rx8 - You need

Quickly De-Flooding Your RX8

First, we are going to disconnect the power from the fuel pump and then crank the engine over to clear out some of the additional fuel that is in the engine, then we will reconnect the fuel pump and jump-start the car to get it started.

Unless you are very lucky, it is unlikely to start on the first try, and could take 10-15 iterations of this process to get it started. Make sure you leave around 30 seconds between cranking the engine over to allow the starter motor to cool down (for more context, check out our explainer on how long does it take for a car to cool down).

How To Start A Flooded Mazda RX8, Step 1 – Charge Up

Put the car on charge beforehand to ensure it has maximum power to crank the engine over.

Starting a flooded mazda RX8 (2)_1000x750

How To Start A Flooded Mazda RX8, Step 2 – Remove Rear Seat

Remove the rear passenger seat by pulling the base of the seat upwards to reveal the fuel pump cover.

Starting a flooded mazda RX8 (3)_1000x750

How To Start A Flooded Mazda RX8, Step 3 – Remove Cover

Use a Phillips screwdriver to undo the 4 screws on the cover and lift off the cover.

Starting a flooded mazda RX8 (4)_1000x750

How To Start A Flooded Mazda RX8, Step 4 – Look At The Fuel Pump

Here you see the fuel pump and the connector that we will be disconnecting.

how to start a flooded Mazda rx8 - fuel pump

How To Start A Flooded Mazda RX8, Step 5 – Set Up Lump Leads

Set the car up for a jump start. I used heavy-duty jump leads as you may be cranking the car over for around 15 minutes on and off, use another powerful car for the jump start, and make sure the other car is running at the time of jumping.

how to start a flooded Mazda rx8 - jump it Flooded RX8 - rx8 flooded engine

If you don’t have another car you, might be able to get away with a mobile power bank. I have successfully done this a few times.

How To Start A Flooded Mazda RX8, Step 6 – Disconnect And Crank

Back in the driver’s seat, ensure the car is out of gear, and remove the fuel pump connector from the fuel pump. Once removed crank the car over with the clutch depressed for 30 seconds to clear out the excess fuel from the engine.

how to start a flooded Mazda rx8 - reconnect after a few minutes - Flooded RX8

How To Start A Flooded Mazda RX8, Step 7 – Keep Cranking And Connect The Pump

Whilst still cranking the engine, plug the fuel pump back in, apply 1/3 throttle and continue to crank the engine with the clutch depressed for 30 seconds. Repeat steps 6 and 7 until the car starts to fire up.

When the car begins to catch, don’t let go of the key until you’re sure it will stay running. It can take many attempts to get it started. See the video below for an idea of how the process looks.

How To Start A Flooded Mazda RX8, Step 8 – Take The Car For A Run

Once running take the car on a good 20-minute run ensuring all fuel is burned off out of the exhaust properly. Fixed.

Top Trick – Get a Boost Pack

I found that I was getting a bit nervous about stalling the RX-8 whilst out and about. Without a jump car, it was impossible to get the car started again. But with a mobile jump pack, I have been able to get the car going again. It might not work in all instances, but you can crank the car over around 20-30 times with these packs for are a great help.

Mazda RX8 Motor Swap

If your RX8 engine is truly broken then you might want to consider an engine swap, we have a full guide looking at everything from V8s, 1JZ, 2JZ, or even 13B-REW engines.

If you are specifically interested in swapping to an LS engine, we have a detailed guide as well. Take a look and plan your new engine. After that pick the best RX8 body kit for your fully running car.

Facts: Reasons a Mazda RX-8 Won’t Start

  • The most common reasons why a Mazda RX-8 won’t start are a dead battery (to find out more, check out our guide on how to charge a completely dead car battery), an alternator problem, or a failed starter.
  • 38% of the time, the issue is related to a dead battery, while 27% of the time, it’s an alternator problem and 20% of the time, it’s a failed starter.
  • If the battery is dead, it may result in dim lighting in the interior of the car, and replacing it can cost between $343 and $354.
  • A failing fuel pump can cause a loss of pressure in the fuel system, which can prevent the car from starting. Replacing the fuel pump can cost between $892 and $1,030.
  • When the ignition switch or lock cylinder fails, the car may permanently or intermittently lose power to certain systems and components, and replacing them can cost between $183 and $279.
  • If the starter motor fails, the engine may not rotate when the key is turned, and replacing it can cost between $426 and $580.
  • When the camshaft or crankshaft position sensors fail, the engine may stall or fail to start, and replacing them can cost between $175 and $239.
  • Correcting most no-start problems usually involves replacing the alternator, starter, or battery, cleaning connections, or repairing the ignition or fuel systems.
  • To avoid replacing unneeded parts, it is recommended to have a professional perform a diagnostic test to identify the root cause of the problem.
  • Diagnosing modern automotive systems without proper knowledge and training can be difficult, and most vehicles have a communication network that allows all systems to communicate, making it challenging for DIYers to save money on repairs.

Frequently Asked Questions

If you’re still curious to learn more about how to start a flooded Mazda RX8, our FAQs here might help…

How To Remove Spark Plugs Mazda RX8

The easiest way to remove the spark plugs in a Mazda RX8 is by removing the wheel. This is because due to the placement of its rotary engine, the spark plugs are mounted on the side of the motor. Therefore, getting to it from the top, as you’d usually do on most cars, can be a bit tough. So, start by removing the driver’s side wheel (if you have the LHD RX8 models or the front passenger’s side wheel for RHD cars). At the back of the wheel arch, there should be a flexible flap. Just remove this flap, and you’ll have access to removing the spark plugs. You can use a 13/16-inch socket to remove the spark plugs, as the RX8’s unique engine has two different types of plugs to remove – four in total.

How To Unflood An Engine

A flooded engine is what happens when there’s excess fuel in an engine after you’ve turned it off. Thus, wetting the spark plugs excessively. To fix this, start by cranking the engine with the accelerator pedal pushed all the way to the floor. From here, continue cranking the engine for another 10 seconds or so. Only stop once you hear that the engine is trying to start up. When the engine’s properly started and running, let it rev up for a couple of seconds. Then, keep on revving it and hold the RPMs until it’s a bit higher than its idle engine speeds for a few more seconds. After the engine is all warmed up, that should clear up the flooding in the engine, so keep on driving normally.

How To Start A Flooded Engine

One technique that you can use to start a flooded engine is by opening the hood. After all, the end goal that you want to achieve is to reset the air-to-fuel ratio. And, to try and clear out any excess fuel that’s left inside the engine. By leaving the hood open for a little while, that might give the excess fuel a chance to evaporate. Now, see if you can start the car again by cranking the ignition – but, while keeping your foot away from the accelerator pedal. If that doesn’t work, try pressing and holding the gas pedal on the floor while you try to start it. Once your car starts, let go of the gas pedal and let your car run for a few minutes to warm up and reset balance out the excess fuel.

Is Mazda RX8 A Good Car

If you’re looking for a fun and sporty (yet practical) car, the RX8 is well worth considering. It has all the dynamic chops and fun-inducing personality that you’d want in any sports car. Yet, it has four seats and ample space to fit your whole family. In all, the RX8 is certainly among the best driver’s cars out there. And, they’re quite cheap on the used market, as well. Although, there are some caveats with owning an RX8. Its fuel economy is pretty bad in comparison to most of its peers. In addition, the RX8 could be very unreliable at times… But, not if you’re diligent about maintenance. Service it well, and the RX8 is decently reliable, though it requires a lot of attention.

Does The RX8 Have A Rotary Engine

Yes, the Mazda RX8 does have a rotary engine. It was also the last Mazda to date to be featured with a rotary engine. Specifically, the RX8 came with a 1.3-liter RENESIS two-rotor Wankel rotary engine. Throughout its production lifespan, there are numerous minute iterations of this engine. Thus, it ranges in output from 189hp to 238hp in its top-most and sportiest variant. This is an engine that could easily rev up to 9,000RPM! Yet, some owners felt underwhelmed with the torque that the RENESIS engine produced. When you’re cruising at lower speeds, the torque is a bit of a let-down, according to some. Hence, it’s the reason why aftermarket turbo kits for the RX8 are so popular.

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  • Ollie Bell Says

    Flooded my engine and followed these steps, had to repeat 6 and 7 a few times but it did the trick. Unplugging the fuel pump is essential! Thanks!

  • luke simms Says

    What is the difference between this method and removing the fuel pump fuse which is much more easily accessible

    • It’s just personal preference really. I found it easier with one hand on the pump connector and the other on the ignition key. Either is fine.

  • Phil Bate Says

    Unplugging the fuel pump or its fuse are unnecessary. Fully depressing the accelerator while cranking disables the fuel injectors for this very purpose. Check the user manual.

  • Del Worville Says

    Don`t you think this advice is a little irresponsible!
    To suggest making and breaking the 12 volt supply to the petrol tank whilst live (cranking) is not the thing to do, a random spark and any possible petrol fumes do not mix believe me!
    This method is totally unnecessary when you can just floor the throttle or remove the fuel pump fuse.
    Someone needs to brush up on safety procedures before tinkering with a petrol tank.

  • drfreud Says

    please don’t think i’m stupid, i can’t get the fuel pump fuse out-literally. I can pul the rest, is there something special about the blue? Laugh later…I’m not paying someone to fix my car, i’m trying.
    (front right blue fuse)

  • my rx8 don’t want to start and am not sure if its flooded or compression loss. and my challenge is that I don’t have the tester and mazda Namibia wont do it because I imported my car from UK. but all I know is I had a misfire, and when checked it was 2 coils dead,and the mechanic used to start the engine with 2 coils but later it couldn’t start, when new coils came the car couldn’t start.

  • Colin Says

    Tow the car at low speed, ignition on, and let out the clutch in 1st gear. All fuel will be ejected rapidly.

    Not every flood can be cleared via cranking, especially in early cars with the slower starter. The tow start has been the most effective technique, in my experience.

    • mark john hill Says

      I am having the same problem ,started my car backed out the garage and stupid turned off when cold FLOODED it s a 2004 231 will it start with a tow?it s my last option

  • I can confirm that an RX8 231ps (mine’s a 2007 vintage) will disable the fuel pump if you fully depress the accelerator pedal BEFORE turning the ignition key. The beauty of this, is that any failed start can be followed by a purge (pedal to the floor before ignition) and then try again. I did 3×6 second purges, then the 4th time I’d do a 1 second purge then release the accelerator pedal whilst cranking which would cause some firing. The successful start required continually cranking whilst the engine revved which I think is superbly illustrated in your video. Thank you for posting this which was a great help (though I didn’t have to disconnect anything).

  • alfredo Says

    i disconnect the fuel pum now it say i have no gas but it used to have gas but now im all confused

  • Roger Says

    I’ve spent two days trying to start my 04 reg RX8 following the advice given. Must have cranked the engine in total for about 2 hours on each day, even Green Flag had to give up. Interested in the tow method but I’m parked facing downhill and without the engine running means I couldn’t brake if I had to. Can anyone help?
    I’m getting desperate now!!


  • Roger Says

    No it’s not fired at all. It’s cranking over very strongly. I don’t think there’s a secondary issue as it was running perfectly before I moved it just 100yds for my son before turning the engine off. I know now that I shouldn’t have done that and that I’m to blame for it flooding. I think also that if there was a secondary issue, then Green Flag would have found it. Green Flag said to just keep on trying (and then left) but I’m worried we could burn out the starter motor.???

    • I agree be extra carefully to give the starter time to cool. I have ran this process a few times now and sometimes its 5 minutes, I think 30 mins was the worst.

      Other things that might help I know there is two types of start motors available, one with more power, might be worth checking which one you have in case you can upgrade both for now and issues in the future.

      I would just keep trying. Video it and send me a link, I would be happy to see if I can assist.

      • Roger Says

        Thanks Paul. I’ll try starting it again later on and will video it. How do I send you a link though? Not done this before on this site. Thanks for your interest/help.
        Email: rogjanjones@yahoo.co.uk

  • Nick Pratt Says

    If rx8 is flooded tow for 500 yards or so dont touch throttle till it fires then will smoke like fuc take for a run till smoke clears and Roberts your farthers brother

  • Mary Says

    Hi, my 2009 rx8 is flooded. It’s automatic and I was wondering if this procedure would still work for it? Do i just keep the gas depressed the whole time while cranking and then plug the fuel pump back in and continue cranking? Please help. Thank you!

  • mark john hill Says

    So people will a flooded mazda rx8 231 start by being towed,come on chaps and lady will it work, ploease HELP

  • lukas Says

    hi i tried everything but when it stars even if i rev it at 3k or 4k rpm when i let the gas pedal go it shuts off please help me what shall i do and before that i was driving and the car shut off by its self while driving

  • Tom Says

    Thanks so much for this it helped fix my 07 rx8!!

  • Andrew Says

    Thanks!! It worked on mine

  • James Hodgson Says

    Thanks for this. It worked like a dream for me. Attached a power pack to the battery, 5,15 second turnovers with the fuel pump disconnected. Plugged back in and started straight away. Had been struggling with other methods!

    • Zack Norman Says

      Thanks for the comment, James Hodgson!

      Glad to hear that our guide has been of some help, and that you’ve gotten your car working again 🙂

  • Gaynor Says

    I have trouble starting my 13 year old RX8 every time I use it. It’s done 37,000 miles. Will this just get worse?

    • Zack Norman Says

      Thanks for the comment, Gaynor!

      It’s hard to say, because whether or not it’ll keep getting worse will depend on the underlying issue. You should have it checked out by a mechanic to see what’s causing that no-start issue, and consider fixing it from there.

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