Rotary_7

Who Revs to 3k and then turn off their car(rotaries only)??? ( while at 3k when car is not in motion)
I heard this helps burn they left over oil in tha engine or sumthing like that....

Black91n/a

It's not advisable, you could get some fuel puddling on the bottom of the rotor housings, and that can't be too good.

BMS2004

how would fuel puddle in the rotor housings? wouldn't the ECU cut power to the injectors which in turn would cut off fuel?

casio

these little things may be why so many people get ****-eyed when you mention a rotary. you _can_ rev to 3000 when you turn your car off, but you shouldnt really need to. just like you _can_ run 2 stroke, but you dont need to. you can also run water through your engine as well as carb cleaner. rarely are any of these things really necessary. i'm in break in (well, 1750+ miles now) on a rebuild and i dont have to rev. start up only gives me trouble in the morning, but i have 2 codes (check engine light). car starts well when warm. decent at least.

Kenteth

yes, and injectors never leak *S*

walken

iTrader: (6)

I thought that was something you only did with carbed engines?

DerangedHermit

If they're leaking it wouldn't matter because they'd do it while it was off in general.

WAYNE88N/A

You can't shut down a jet engine until it's been at "idle" for at least 45 seconds due to what's known as turbine rub (caused by thermal discrepancies between the spinning blades and the engine casing). While this may have nothing to do with a spinning rotor sharing close tolerances with a rotor housing, to me it's an analogy, therefore I always let her idle and come to thermal equilibrium before shutdown. In other words, no revving before shutdown...

casio

so youre saying i must let my motor reach Zen before i turn it off?

Relisys190

iTrader: (4)

True story

DerangedHermit

Glad it worked out in the end.

Lodivigo

Hmmm, funny topic, I work at a Mazda dealership and we get a fair share of flooded RX-8's from time to time. After we deflood them, clean up the plugs and send the car along we are *required* to give the customer a little pamplet from Mazda telling the customer to get the engine warmed up as much as possible before shutting down. If however you have to shut it down cold, it recommends revving the engine to 3,500rpm before doing so.

Not really sure I buy into this advice though as I've never done this after a short trip. My 7 has never flooded on me BTW.

Gregs

i usually always give mine a little gas then cut the ignintion...

91mazdarx7

im not sure about n/a's but i read it somewhere on this site that says after hard driving on a turbo engine you have to let it sit and idle then turn it off but aint that what a turbo timers for

TurboSmoke

i never shut off my car at a higher rev then idle. i always just give it a quick rev to 5k then let it idle for 30-45 sec.

1RevvinFC3S

: Oh, that chick in your avatar could make a blind nymphomaniacal non-picky middleaged guy Lodivigo.

jon88se

It shouldn't be harmful...it just allows the engine to drink any excess fuel to prevent flooding on the next start.

slidebabyslide

i have never ever had this problem "knock on wood" but i never have alot of gas in my car any ways , can u run engine restoresin rcro offtopic,run mycar hard as **** lil thing still holds up, my turbo swap only last me 2 hours lol i tham jdm engines ok thaks

kevino

so rx-8's are already flooding? I guess Mazda didn't do a damn thing to fix the flooding problems of the rotary.

Jodoolin

Lodivigo. are you saying the RX 8 shares the cold shut down flooding problem with the RX 7. Geeze, one would have thought Mazda would have resolved that issue. I can't believe cold shut down continues to plague rotaries!

GTUser

That quick warm up cycle on cold start must be essential for building up the thermal equilibrium on the rotors and housings. Even the RX8s need it to operate at an efficient level.

I don't understand why you'd need to let it idle again before shutdown. Seems like it would be thoroughly, uniformly warmed up after several minutes of driving and the shutdown idle would have very little effect on the thermal loading of the engine components. No reason to rev it up before shutdown either since this accomplishes nothing with leaky injectors or a properly working engine and support systems.

Am I missing something?

jon88se

But flooding is not usually caused by leaky injectors - the real cause is usually low compression and/or not warming the car up. My car will hot start just fine, idle vacuum is good, it drives well and is just out of break-in so I assume my compression is just fine. BUT, if I must shut the car down before it's warm, I use the 3K method and it works. You're allowing the engine to spin down from 3K and that decel speed lets it drink any excess fuel as opposed to shutting it down from idle.

WAYNE88N/A

What are you refering to as "excess fuel"? It takes more fuel flow to rev her to 3K just before shutdown than it does at idle, and as we're all aware, these gizmos aren't the most fuel efficient contraptions around, which means there will be that much more unburnt fuel making the rounds at 3K. It's not like the fuel in the rails is being "bled down" or the like, the pressures behind the injectors will be the same if you shut her down at idle or 3K (the FPR corrections notwithstanding).

It's something in the software, it's got to be. I drove her 50 miles home one night last winter and happened to run her through some cold flood water 8 miles from home (OAT was maybe 40*F). That water caused the rad temp switch to open, even though the rest of the sensors were fully warm, and she flooded on shutdown, the last time she's flooded on me... The theory I've used ever since then is you have to warm the car up until the rad temp switch closes (about 60*F), that's the deciding factor as far as I'm concerned. Water thermo switch has a say in things, too, I would guess.

I really see no outstanding problems with revving to 3K just before shutdown, as long as you're not trying to shut her down immediately after a hard run. 3K in neutral is not really a load on the engine, therefore won't create the kinds of temp extremes that could play havoc with close tolerance components. Remember, we have aluminum housings sandwiched between cast iron- you REALLY want temp stabilizations between those bad boys at all times, especially at shutdown....

HAILERS

http://rx7.com/techarticles_floodprev.html

and no, I don't use this or any other unflood procedure because my car does not flood. The above from RotaryPerformance mentions the three grand.

2ndGen.rocket

Or you could just install a fuel cut and not worry about it. I use that to turn the car off regularly, haven't flooded in a long *** time.