How To Prevent Flooding
 

I trust the guy who sold me my car, and for those of you who are unaware, let me explain why it floods.

When the rotary engine starts, a lot of gas is pushed into the engine. If you don't burn it all away before shutting the car down (or stalling, the bigger problem), you will have a flooded engine. If you start your car, then put it in neutral and get the RPM's to about 3K for a few seconds, you will see the RPMs jump around for a bit as the excess gas gets combusted off. It is A LOT easier to flood in cold weather, as it takes longer for the gas to combust out. I have done this "get rid of excess gas" proceedure every time and have not had a flooding problem.

I see, so basically the solution you propose is to hold the RPM at around 3,000 and wait till the needle steadys out and then we are safe right ?

Sounds simple enough and right to the point.

Some have said to hold it at 3000 rpm as you shut down. That seems more relevant to avoid flooding at the next startup.

Define "a few" seconds. I'm guessing more than 2 and less than 60.

One of the guys at my dealership who I've become friendly with said that they have been getting towed in pretty good number with flooding problems. He said that the spark plugs are part of the problem because as he put it “they just don’t come clean” I don’t know enough to know what he meant exactly.

I spend a lot of time on long trips far away from home (snowboarder) so he suggested a fix that he said was used in rx7’s where a switch was put in to shut off the fuel pump. They would even do it for me for all of $200 bucks. Which if any knows if that’s a good idea, let me know.

Either way, thought I should toss this info in the thread.

Killjoy, are you saying the dealership said that they -- the dealership -- would install the kill switch? Or are you talking about people outside the Mazda organization?

He works for the dealership, and it would be their people doing it. Now if it's "though" the dealership so to speak. I didn't ask.

I've cold-started my 8 numerous times to get it out of the garage for a wash. It has never failed to start. Where I live the weather is quite warm so flooding indeed probably occurs in colder weather. Anyway, I'll be more careful now when cold-starting the car.

Why would you want to put a switch to turn off the fuel pump? How would that help? are you going to turn off the pump half way through turning the key or something? I mean the problem isn't fuel leaking into the engine when it is off....soooo...i don't get it....

There are a lot of Warning and Caution notes in the owner's manual, but I can't remember reading anything regarding cold-starting. If flooding is such an issue, why does Mazda not mention it in the manual? How are novice rotary-engine drivers supposed to know these things?

my guess is the kill switch would be for if you flood it you can turn off the fuel pumt, turn the engine over a few times to burn off the excess gas then turn it back on and start the car.

Holding the gas pedal all the way down is suppose to turn off the fuel flow and clear the excess when cranking. This would make the switch a waste of money and time??

IMHO, the problem is more than the flooding, it's the spark plugs getting fouled and not firing. This is because the procedure for shutting off the fuel pump doesn't seem to do the trick. This means no fuel is coming into the combustion chamber and theoretically the gas is purged from the system.....but what is not accomplished is unfouling the plugs. All threads that mentioned taking it to the dealer said they removed the plugs, cleaned them off, and put them back in. I guess the mix of oil and gas at startup (or cold shutoff) gets stuck on the plugs. I also remember reading about new plugs you can get at the dealer that burn hotter to reduce the chance of fouling. I would suggest anyone with this problem to talk to their maintenance rep at the dealership.

Don't do this unless you've actually flooded your car.

Thought I'd throw that in for those who interpret this as how they should always start their car.