Starting a Mazda RX-8 with a flooded engine

October 12, 2010 · Posted in Transport 

Mazda RX-8

Mazda RX-8

A few weeks ago, I made the mistake of moving my RX-8 a short distance and didn’t allow the engine to warm up before switching it off. It’s well-known that this can lead to a flooded engine and this time was no different. :-( I knew it was a mistake, but I was in a hurry!

I’ve only had this happen once before and, as then, I couldn’t get the engine restarted using the manufacturer’s technique of fully depressing the throttle (should cut the fuel), cranking the engine for 10 seconds (should clear the flood) and then cranking as normal. Having tried this a couple of times, I soon ran the battery flat and so had to recharge it overnight.

Next day, I tried the tips from this excellent blog post. It describes how to unplug the air pump and remove the fuel pump fuse to assist with starting. I tried this but again failed, mainly due to lack of charge in the battery even though it was fully recharged. The same technique was used by the RAC chap who got me going the first time this happened – it took him about 20 minutes and of course he had access to a much better power source on his van.

Now out of options, I called the AA. The chap they sent out took a rather different approach which I’ll attempt to describe here in case anyone would like to try it:

RX-8 fuel pump cover under seat

RX-8 fuel pump cover under seat

1. Remove the nearside rear seat base cover. The lower seat cushion simply pulls up (see comment 57 from KenF below).

RX-8 fuel pump cover without screws

RX-8 fuel pump cover without screws

2. This reveals an access panel which is held in place by 4 sheet metal screws. Remove these screws and the panel.

Underneath RX-8 fuel pump cover

Underneath RX-8 fuel pump cover

3. There is a single electrical connector (black plug with 3 cables connected to it) on the pump assembly that provides power to the fuel pump and readings from the left-side tank level sensor. Take a moment to learn how to disconnect and reconnect this connector.

4. If possible, connect an additional power source to the battery (another battery or another car via jump leads).

5. Position yourself in the driver’s seat with your left hand stretched behind you (assuming you have a right-hand drive vehicle) ready to connect/disconnect the fuel pump. Keep it in the disconnected position.

6. Apply around 1/3 throttle on the accelerator pedal. Use your right hand to turn the ignition key.

7. The engine will turn but not start. After around 10 seconds, connect the fuel pump for a few seconds then disconnect.

8. You may need to repeat this a few times. Don’t crank for more than about 30 seconds at a time though to save your starter motor!

9. After a few tries, hopefully you’ll hear the engine getting close to starting. The point of connecting and disconnecting is that you are trying to clear the engine and then reconnect at just the right time to get the fuel pumping again (see Andy’s comment, 8 below).

The AA chap said that using this technique he can usually get RX-8s restarted in around half the time it takes using the fuse removal, etc. Apparently he learnt this from a chance conversation with an engineer from Mazda. I suspect it’s the sort of thing you need to try a few times to get it right, but it certainly seems to offer more control over the process as you can access and change all inputs at the same time (fuel pump, throttle and ignition).

Let me know if you try it. As always though, it’s at your own risk – I don’t want any repair bills for a knackered fuel pump or catalytic converter :-)

If you leave a comment below, it would be great if you could add which country you are in, there are quite a few here already!


218 Responses to “Starting a Mazda RX-8 with a flooded engine”

  1. spinage on January 3rd, 2013 09:38

    Thanks Paul, that’s really helpful extra detail.

  2. robbie on January 3rd, 2013 17:47

    Firstly thanks a million just got my rx8 restarted after i flooded it took a bit of effort but shes purring again only problem is engine management light is on is this because my battery died whilst trying to start? is it an easy fix thanks a lot!!!

  3. spinage on January 3rd, 2013 19:53

    Hi Robbie, I seem to recall that the engine light stays on until you’ve started then stopped the engine a few times. After that, it goes out if there is no longer a problem.

  4. Andrew on January 5th, 2013 20:50

    Hey guys. In the uk here .. i have runflat tyres on my baby and i drove a few yards last week n noticed one of the tyres had burst so i just reversed back into my driveway a left it … about a week later i went to take it down to get the tyre fixed and BOOOM nothing .. so i charged the battery … now im getting that sound that is on youtube that means the engine is flooded … tried the fuses method and all that .. well nonsense 😛 .. ive not took the spark plugs out yet .. i think ill try this method first !!! im really worried ive totally fooked the car :( … ill give it a blast tomorrow then ill let you know !!! cheers in advance !!!!

  5. Andrew on January 5th, 2013 22:12

    sorry to be a pain mate but also … al lot of fourms say wait till it sounds like theres compression back … what does compression sound like lol?

  6. Andrew on January 5th, 2013 22:14

    and def the last thing … when i crank it with no fuse for fuel in .. theres no white smoke ??? should there be?

  7. Mark B on January 7th, 2013 08:35

    Thought I would post my experience of this issue…I had the RAC out to my flooded RX8 last night. The mechanic said that the procedure of starting the car with the accelerator pedal fully depressed has the same affect as disconnecting the fuel pump. He said he been dealing with rx8 floods for 6 years, he said you just need jump leads as battery will flatten pretty quickly otherwise.

    He basically connected jump leads and turned the car over 10 seconds at a time with pedal depressed, he repeated this several times, resting the starter motor for a couple of minutes each time. Finally he cranked the car without pressing the pedal at all. Car spluttered but didn’t start. He just repeated above 3 times, each time engine sounding better, with more and more smoke coming from exhaust.

    In my case it took about 20 minutes, but he said it can take much much longer. I showed him this blog, but he said effectively what he did was the same thing without the additional hassle. Cranking the engine on the starter motor WILL eventually unflood the cylinder – it just can take some time. He also mentioned some older rx8 had less powerful starter motors and that can have a bearing on how long it can take.

  8. spinage on January 7th, 2013 09:35

    Hi Andrew, try looking through some of the comments here, there’s some really good extra tips. Hope it gets you going again!

  9. spinage on January 7th, 2013 09:39

    Hi Mark. I’ve had that experience too, as you say it can take 20-30 minutes, which is often more than the battery can bear (unaided by a spare power source). This technique is often quicker therefore handy when you don’t have long :-)

  10. Brad on January 10th, 2013 22:45

    Like several of the above owners, my 05 RX-8 flooded due to my father-in-law starting it while we were on a family vacation and not properly shutting off. The last 3 days were stressful to decide what to do, as we live in rural Ohio and the closest dealership is 50 mi. After purchasing a new battery and trying the pedal-to-the-metal approach, I was close to throwing in the towel and calling for a tow. I decided to do a bit more searching, found the idea about the #22 fuel pump fuse removal, but repeated attempts didn’t pan out. Finally I stumbled across this crazy idea of a back seat fix. I initially thought it can’t be any better than the other methods, but after reading all the success stories, I had to give it a go. I stuck my wife in the back seat to control the fuel pump connection while I worked the ignition and gas pedal. I tried about 6-8 attempts with the pump disconnected, each about 10 seconds long and resting the starter 10-30 seconds between each try. Then we tried 3 seconds, connected it, and had some good sputtering noise. We followed the same approach another 2 times, and finally got it. From the time we got the access plate off, the it took 15-20 minutes until the engine turned over. It was great to hear that purr once again! I agree that a strong battery, a 2nd person, and depressing the gas pedal 1/3 to 1/2 are keys to success.

    Anyone reading this blog and wondering if it works, I’m proof positive. Spinage, a huge thanks to you and for everyone else helping out your fellow RX8ers.

  11. spinage on January 11th, 2013 10:53

    Thanks Brad, that’s a great story and hopefully the extra detail should help others too!

  12. Jon on January 19th, 2013 19:32

    Started it in about 30 minutes!! Didn’t want to mess with the rear seat/fuel pump scenario, so I fabricated a jumper from the fuel pump fuse. Really simple and works like a charm. Gonna keep it in the car in case I need it again. Just remove the fuse and install the jumper. Then crank the car with the circuit open to stop the pump and get rid of the excess fuel. Rest the starter a bit, then try again while listening for signs of engine life. When you hear the engine firing, close the circuit very briefly and repeat until it improves. May have to stay on the starter a few seconds until the engine smooths out. Took a couple of tries but no big deal really. Enjoy!!

  13. spinage on January 19th, 2013 20:13

    Thanks Jon, great idea to make a jumper that you can keep for future use.

  14. Alan on January 22nd, 2013 16:12

    Hi, I tried this method and got the car to initially fire up but it wouldnt catch properly and died. Couldnt get it restarted again so had to succumb to the dreaded Mazda garage. They took out and dried the plugs and then checked the coil packs and found 2 of them faulty along with 2 dodgy plugs guess there was little chance of starting it with those probs!!. Car had been for a service about 6000 miles ago and they hadnt found any issues, makes you think huh. Anyway, I’ve ordered a new coil pack which will be delivered tomorrow and hopefully they can get her started. Didnt buy the Chinese ones!! but was able to buy 4 for the price that Mazda wanted to charge me for 2, got them from RBMotorsport. Anybody tried the Volo VP12 chip upgrade yet?

  15. David on February 3rd, 2013 14:14

    I’ve never shut down my RX8 while cold due to it flooding the engine, but unfortunately I didn’t tell my dad this when he moved it off the drive while I was away. It’s pretty worrying when you come back and find it won’t start but this technique came to the rescue.

    Just wanted to say thanks to the owner of this blog and other posters, this technique worked a treat and was realtively simple to do.

  16. spinage on February 3rd, 2013 17:03

    Thanks David!

  17. Jack Savage on February 6th, 2013 09:22

    You are literally my hero! My girlfriend’s Dad moved my car 10 metres and turned it off in the cold weather without leaving it to warm up. Went to start it the next day and got nothing but starter motor! Got myself some jump leads and put your technique into practice and with a big cloud of black smoke she spluttered into life… Took a fair few attempts but it all worked in the end so just keep at it. Good luck!!!

  18. spinage on February 6th, 2013 10:34

    Thanks Jack, that’s great to hear!

  19. Mark on February 15th, 2013 21:33

    Wicked, worked a treat, took about 20 mins but only coz the leads I was using were Kak, left the pump disconnected turned it 3 to 4 times for ten seconds each then connected the pump, turned it over again with NO throttle twice then half throttle 2 more times and it went, when it did I went to about 5000 rpm for 20 secs then left it to idle for a further 5 mins and then took it out for a good hammering, running sweet again, thanks a lot !

  20. Andy Minor on March 4th, 2013 14:05

    We had some building work done and I had my leg srapped up with torn ligaments so the builder moved my 2005 RX8 and lo and behold wouldn’t start a few days later (his ears must have been burning )After much cursing I came across this thread and gave it a go.To cut a long story short this worked a treat and I’m truely grateful.

  21. spinage on March 4th, 2013 14:14

    Great to hear Andy – hope your leg is better too!

  22. Bazza on March 21st, 2013 16:17

    I hope this works. I was moving cars around on my drive because I needed to do some work on one of the others cars. Tried to start the 8 after I moved it but no go. Tried all but to no avail, will try yours after I charge the battery up.

  23. Martin on April 3rd, 2013 08:56

    Just read through all the success stories and was also put off initially by the description of the process despite being an engineer who used to change his big ends regularly (30 years ago mind)

    Process is actually a doddle but watch for the sharp edges on the fuel pump cover – added a little blood to my sweat from the previous day!

    Engine fired up immediately – didn’t have to wait at all. Probably helped by trickle charging battery overnight and having first day of sun in London for many months….

    Great one Slipage!

  24. Damien on April 4th, 2013 22:50

    This is a life saver. Flooded my wifes RX8 this morning moving it so I could get my car out. She was not a happy bunny

    Get the jump leads out and persevere with this method it works !!
    Thanks so much

  25. Matt on April 15th, 2013 23:49

    The advise on here has really helped.. It took a bit of time to get going but after taking both the fuses out you could feel that my rx8 really wanted to start up again.. 3 more cranks and we were off… Honestly couldn’t of got my car going again with out the tips on here…. Cheers

  26. viv on April 23rd, 2013 06:44

    Flooded the car for the third time, (first time coz i was stupid and second time by a mechanic who didnt know his rotary- cost over $6000 all up for a new starter motor and labour so very upset)

    def shouldve known better but was in a rush to move the car out of the way for the brother to get his car out and go back to sleep.

    I really didnt think this method would work after seeing no change in engine sound using the fuse in fuse out method, it was hopeless. but after reading how many successes there was on here i gave it a last ditch effort before calling mazda to tow it

    pleasantly surprised to find that we got it purring within 15 mins! AMAZING! THANKYOU SO SO MUCH you saved me lots of money!

    having a friend in the back helped alot, i recommend this to everyone! <3

  27. Rob on April 24th, 2013 03:09

    You rock. This is the third time I stalled it after a short move. First time $300 or so for the dealership to drain it. Second time $1500 for drain and eventual plug/wire changes and maintenance. Third time was a Sunday so I had time to try this. 30 minutes later the car was purring like a kitten. Note that the check engine light may come on, but after a day and a few starts it cleared. Thank you from Milton, Ontario, Canada.

  28. Bruce on May 9th, 2013 02:05

    Wow. This was my 3rd time to flood my 2004 Rx8 – the first time cleared quickly with the pedal-to-the-metal trick, but the 2nd time happened away from home and resulted in the costly trip to the dealer, fresh plugs and a drained bank account. This time happened in my garage, and so I wasn’t about to call for a tow. Disabling the fuel pump wasn’t much help.
    Since I’m in the US, the position to get the clutch down, the accelerator pressedr and the key turned was pretty awkward, but it worked after awhile. It’s straightforward, once you get the hang of it……

  29. spinage on May 9th, 2013 06:32

    Thanks Bruce, that’s interesting. I can imagine how it would be a more awkward stretch from the driver’s seat on the left rather than the right. Glad it still worked though!

  30. Bruce on May 9th, 2013 14:25

    Once I had the seat back, it wasn’t as painful as i had expected. I’m feeling pretty good today. But it would be much more difficult if that connector wasn’t within reach. Thanks again!

  31. Anthony on May 20th, 2013 22:25

    Just about to give up and list my rx8 on eBay as a non runner and stumbled upon this post and thought I’d give it a go.
    Waited for the wife to come home with her car for the extra power from her battery, got seat out practiced removing plug and went for it! Took around 10mins and the rx8 spluttered into life like a swimmer having CPR after drowning in a pool. Gave it some gas then let it settle on tickover whilst the street filled with smoke.
    Took her for a blast and couldn’t believe I did it! Awesome. Thanks for taking the time to write this info, so chuffed to have my car back on the road. Thanks a lot man.

  32. spinage on May 21st, 2013 06:33

    Thanks Anthony, great story and pleased you’re up and running again!

  33. TimboMachino on June 3rd, 2013 00:18

    Spinage, you’re amazing, thanks so much for this blog. Here’s what happened to me…
    I moved to Northern Ireland back in November ’12 and I’d been here just 2 weeks when the Rexy died on me. I suspected the coil packs, as I’d had everything else done a few months earlier. Trouble was, I couldn’t afford the fix at the time. £350 for the coils and the leads was just too much as I was still looking for work.
    So my beloved RX8 has been sitting on the drive for 6 months while I had to suffer using the Wife’s car. Recently I was finally able to get the kit I needed and did the work.
    When my car was first recovered to a local garage they decided it would be a good idea to keep on turning the engine over with the fuel pump fuse removed. It didn’t start, obviously, and they advised me that she’d probably need a re-build. Anyway, I had no idea if they’d flooded it, or even done more damage.
    After re-fitting new coils and leads I came to stat her up and – nothing.
    Did a quick online search and found your blog here and followed the instructions and, after a lot of patient turning over – finally I hear the sweet sound of the Renesis once more.
    At one point, towards the end, I was thinking ‘this is never going to work’ and that’s when it did.
    If I could I’d buy you a good few beers, you deserve it. Thanks once again and I hope this blog will help many more people who, like me, were close to spending a bunch of cash on a mobile mechanic or giving up all together.
    I love you Spinage!

  34. spinage on June 3rd, 2013 09:19

    Thanks Tim, what a great story and outcome. You’re most welcome!

  35. TimboMachino on June 3rd, 2013 17:58

    Btw: as a post-script to my post above, I’d just like to add this:
    If anyone suffers cat damage as a result of flooding I can highly recommend cats2u. They only do cats but their customer service is brilliant.
    I bought one off them last year coz mine had the dreaded rattle and they sent me one out by courier. A couple of weeks after fitting the new one was rattling as well. I called them up and they sent out another one (more expensive type than the first) at no cost.
    All they asked for was an emissions read-out to prove the cat was broken.
    Hope this may be of help.

  36. Mark Mumford on June 17th, 2013 07:16

    Flooded my 2005 RX8 – bad coils and carbon buildup requiring an engine rebuild (paid by Mazda under warranty) but now I have this terrible feeling that the thing isn’t going to start. Love the RX but the reliability issue is a drag. Does anyone know why this method works? By turning the engine dry for 10 seconds repeated several times, I understand that the engine spins out the accumulated fuel. But once the accumulated fuel is out, why doesn’t the engine start? Some of the posts suggest to reconnect the fuel pump when you “hear” the engine sputter – is this sputter the plugs (now drying) beginning to fire again? I understand that one of the reasons the rotary will not restart is loss of compression. What causes the loss of compression and how does the engine regain compression? Any insights?

  37. Nikki Murray on July 19th, 2013 17:44

    Oh my god, thank you so much, I have had this car 2 weeks, thought I was playing by the rules re engine hot enough, but I flooded it, waited till hubby got home and did as you said with the pump, amazing we did it straight away, so happy, as didn’t want it taken to the dealership £££££ and we r on hol 2moro morning, was so stressed, ssssoooooooo happy I read this discussion. Thank you thank you thank you. I spoke to a friend of mine on fb who I haven’t seen for a long time but know she has an rx8 too, she said she has had hers for years with no problems but the dealership told her from word go that you should always run the engine for a couple of minutes before setting off, and give it a couple of big revs before turning off, she does this every time and has never had any problems. Thank you again.

  38. Nikki Murray on July 30th, 2013 20:23

    And back to square one again after returning home from holiday, just about got it started this way this time nearly gave up,took it out for a long rag, and gave it a couple of revs before turning off, wouldn’t start today, good job we have a second NORMAL car, starting to think this beautiful car is not worth the hassle :-(

  39. Sonny on September 9th, 2013 03:39

    Hi, I’ve got a 04 RX8 (42k) I’m from London and today got a problem with the RX8! turns out I’ve flooded my engine as moved the car and turned it off straight away. From starting it to turning it off lasted not even 2mims. Normally I turn it off when it’s warm but for some reason I f****d up :( anyway I came up with a very easy way to get car started after flooding problems and no compression. I put the tow bar on and attached it to my brothers skyline. He pulled me down the round and I started it by putting it in 2nd gear and bumping it. I couldn’t beliv my luck as only thought of the idea sitting on the sofa with a cold pint. Worked straight away and now car starts fine Everytime. Try it and let me no it it works for you too.

  40. Jas on September 17th, 2013 03:35

    I’ve had the engine on mine flood after watching a video on YouTube and trying out stuff myself since I don’t want to take it to Mazda and pay $800 I realized it takes a few things and about 30-40mins. But be patient it will work I have done it on my car and some random rx8 I saw with a cute broad stranded in downtown vancouver one day 😉 works every time

    1.put jumper cables on car with another car even if battery is fine
    2.hold throttle down and pump 8-10 times before turning ignition
    3. Do this at least 5 times and then stop and step on the pedal and hold it for about a minute just continuous holding.
    4 repeat number 2.
    5. If it still doesn’t work you need this next step open gas door and take off the gas cap, all the built up carbon will release and you when u go to start it might not start but it will sound like its about to.
    6. Put gas cap back on and do step 2 again.
    7. Take off gas cap and do step 2.
    8. Your car finally started! You will get some white smoke coming from the exhaust it’s just carbon dont worry about just make sure when your doing this its not inside the garage do it outside somewhere. Let the car run for 10 mins and use as much as as you can empty the tank as much as possible and fill up with 94 octane to clean out the engine. Hope this works for you guys as it has worked for me numerous times cheers :)

  41. spinage on September 17th, 2013 06:38

    Thanks Jas for an alternative method.

  42. Alan Ramsay on September 19th, 2013 20:45

    I moved my car a few feet to let the neighbour have more room and i forgot !!!,anyway i knew there was a decent answer to my prayers as a friend at work has one and fooded his and sent me in thisdirection and thank you very much !!! 5 times i plugged and unplugged and away she went with a huge cloud of white smoke took all of 4 minutes start to finish -pun not intended but you well saved my bacon , works a treat, all i can say is i live in the north east of scotland 70 miles from a mazda dealer , save this and print it off , THANK YOU !!!!

  43. spinage on September 20th, 2013 13:43

    Thanks Alan, great to hear from you and glad you got it going again!

  44. julius on September 22nd, 2013 12:47

    hi guys, thanks alot. the fuel pump fuse disconnected and reconnected works, the problem am finding is my little monkey rx8 2004 is sparking like bullets and it really scares me to drive it because of neighbours. what could be the problem? help plse.

    thanks .

  45. Fred on September 28th, 2013 20:56

    This method worked great for me. 2006 RX 8: First time flooded in 7 years. (I also jump it up to 2500 – 3500 rpm before turning off when not at normal operating T. This time my wife moved it forward 20 feet and just turned it off.) Took about 20 min. Would have worked faster, but I chickened out the first two times it started and let up on the throttle causing the engine to die. Would not start again until I went through the method again. I do wonder what the unburned fuel through the catalytic converter will do to it.

    Thanks!! (Southern California)

  46. Trevor on October 10th, 2013 03:30

    Thank you so much just tried this on my girl friends car after trying the other methods first it took me awhile to get the hang out of it but worked awsome really saved me had no idea what I was getting into with the rotary motor!

  47. Trevor on October 10th, 2013 03:31

    From eastern Washington

  48. steve on October 19th, 2013 10:27

    Hi.great advice that works!Just had a thought.Fit a pump kill switch,and stop the car using that before turning ignition off when cold.Should stop possibility of flooding?

  49. spinage on November 3rd, 2013 13:49

    Thanks Steve, that’s an interesting idea! Let us know if you try it and find it works?

  50. CJ on November 7th, 2013 02:15

    Well, daughter flooded the RX8…again. First two times it went to the dealer. Yeah, that hurt. In extreme refusal to hand over my cash to them again I dug pretty deep and found this post (don’t know how I missed it the first two times). I’ll be trying it in a day or so when I can get over to the college, hoping my lick holds as everyone else s here did.
    Steve – upgrade to your switch idea. Use a momentary switch as the cut off. That way you avoid the problem of forgetting to turn it back on next time you start it up.