Redfusion3

iTrader: (2)

When I picked my 8 up from the Dealership he told me that when I am done driving and I shutoff my car rev my engine then shut it off to prevent flooding. You guys evey here of this?

and also what kind of gas do you put in your car, Notice any different between 87 and 93 octane?

Ned M

iTrader: (2)

Pedal in a butt-load of gas and shut it off? Makes no sense. If the motor's warmed up when you shut it off you shouldn't have flooding probs.

epitrochoid

RTFM

you hold the revs at 3500 for 10 sec (i usually do less) and kill the ignition. the engine will spin out without fuel going in. it does help prevent flooding, but dont rely on it.

BoxerGT2.5

I always do it and have never flooded the car. But then again I always put on might right pads/skates on first and then my left , so I just might be too superstitious.

Redfusion3

iTrader: (2)

But, I am saying...well it HELP, I know nothing can ever PREVENT a problem. I am just wondering if I should be doing this?

epitrochoid

its not a bad habit to get into. the manual suggests you do it when it's absolutely necessary to shut the car off cold. i figure, if i get in the habit of doing it whenever i shut the motor down, I'll do it if I'm ever not thinking and shut down cold

Redfusion3

iTrader: (2)

Thank you exactly my point, Although I'm sick of explaining to everyone why I do it that rides in my 8.

Crichton

Easiest thing I do is let the engine warm up to normal temperature before shutting down. Never had a problem with starting.

Redfusion3

iTrader: (2)

Neither have I, but I dont have many miles on my car either. I am just trying to keep my 8 in the best state as possible.

blue flash

yes rev it to 3000rpm's for 10-15 seconds if the engine is cold

MyRxBad

iTrader: (1)

You want to refer me to the page that this is on.
I'd never do this.. You are spitting unburnt fuel into the cat. If anything you are going to ruin the cat (read unflodding procedure TSB) and notice that once the car is unflodded using this procedure that they have to drive the car and test the cat to see if it's within spec.

Just make sure the car is warm before shutting it off.

Redfusion3

iTrader: (2)

Whats warm? How many min? Make sure heat comes out then?

wakeech

once the needle starts to move it's warm.

boys who're doubting epitrochoid's recommendation, have a little bloody faith eh??

http://www.finishlineperformance.com.../01-011-04.htm

and for those that don't know RTFM means Read The Fuckin' Manual. this is a very basic matter, and there's nothing to despute.

to repeat what Big E said before is that there is no fuel getting into the engine once you cut the ignition, so there is nothing for you to worry about with the cat or increasing your chances of flooding... the motor simply has more momentum going when you turn it off, and spins for slightly longer when off, hopefully pushing out any gas which might be lingering reducing the chances of flooding.

IKnowNot'ing

So, what's the point of this engine revving procedure then. It's not the first time it is mentionned on this forum, but I REALLY don't get the point of it.
Sorry WakeeCH (got it right this time, haven't I?) but I'd appreciate if someone could explain, step by step, what is going on in the engine when you apply this proceudre, AGAINST what's happening when you don't apply it, and point out the actual differences.

Redfusion3

iTrader: (2)

I would like to know too and get the facts straight both sides have vaild arguments.

MazdaManiac

iTrader: (3)

Very simple.
When you come to a stop, the engine is idling which the state in which the Renesis is its least efficient. If you turn it off at this point, it will come to a stop after only a few more revolutions after you turn the key which is the point at which the injectors stop spraying. This leaves some fuel behind in the motor.
If you rev the motor up without a load up to the top of the RPM range that only uses the primary injectors, the PCM only adds a very small additional amount of fuel over the amount at idle.
However, turning the key at this point will leave you with a hundred or so additional revolutions after the injectors are turned off, pumping all that air through the motor, removing any residual fuel.

epitrochoid

i think maybe the misunderstanding is that revving before shut down on a regular basis will prevent flooding in the future. it will not. you can rev-kill it everytime you drive it, but shut it down cold once and let it sit and chances are it will flood. there really arent two sides to this arguement, just think about how it works. more airflow and no fuel will clean out the chambers much better than less airflow and no fuel. the benefit is neglible once the motor is warm, but like I said, it's a preventative habit. just like looking back at the car after you lock it to make sure the lights flash.

what irks me though, is that since our cars are practically a model for artificial intelligence, why didn't Mazda just program the PCM to do this automatically whenever the motor is shut down under a given temperature?

Redfusion3

iTrader: (2)

Got it.

MazdaManiac

iTrader: (3)

Because letting out the clutch so you can park it in gear can be profoundly problematic if the PCM decides to take the motor to 3000 RPM at that moment!:p