VRExile

Hey everyone, so just a low down on my car. Its an 04 MT with about 70k miles on original motor.
I'm having issues having my car dropping rpm when the car is on.

The start up is fine, no issues but once the 8 warms up i notice that the RPM's drop significantly and shuts down. At first i had issues starting up the car in which, it would struggle starting up but then it would catch it really late.

So i figured at first it was just the battery, so i took it to get it checked and they did say it was low on battery so i had it recharged.
Once installed they start up was perfect. Didn't have any problems but i noticed on my gauges that the traction control light was on and the DSC OFF kept blinking.

So now once the engine warms up the "DSC OFF" light and the traction control symbol turns off BUT the car shuts down once i'm on neutral because the RPM doesn't stay above 1RPM.

Does anybody have any suggestions or probable reason?
People have been telling me it might be engine flooding but the "symptoms" don't add up.


So if anyone can help me with this problem or even figure it out it'd be great
Thanks in advance!
hoping my 8 will run great soon `

RIWWP

iTrader: (2)

A) It's not flooded, since a flooding is excess fuel preventing a proper spark from being able to start combustion. If it runs at all, it's not flooded by definition.

B) Pulling out the battery involves disconnecting the battery. Any time the battery is disconnected it clears many "learned" settings in the ECU, including the fuel trims (needed to keep stable idle), TCS wheel speed calibration, and DSC steering wheel angle calibration. Turning the steering wheel completely from one lock to the other sets the DSC, rolling more than ~10 feet sets the TCS system, though you have to shut off the car and restart for it to switch fully on after this.

Your idle stability is likely just due to the recently disconnected battery. Drive around for ~10 minutes (varying speeds, like city / backroads, use all the gears, etc...), shut the car down for a minute, drive around for another 10 minutes, shut down again. Your idle should smooth out noticeably, and will continue to be refined over the next several days of driving.

If you STILL keep having issues, especially hot start issues, then it's likely to be falling compression. Have a dealer do a compression test. You might still be within warranty, though possibly not (2004 + 8 years = 2012, so depends on when the date of first sale was).

Also, how old are your coils? Plugs? Wires? Clean your e-shaft sensor? Clean your MAF? Check for vacuum leaks?

VRExile

Thanks for that info.
Update on the progress, i actually took it around the town. It was really difficult actually since everytime i had to break my car would turn off so i would constantly try to have my foot on the gas pedal so it wouldn't shut down. But anyways, took the car for a drive and still nothing yet. kept turning off, and i realized that it started having that issue with start up again. It would keep trying to turn on and it would take a while but eventually fire.

The previous owner told me it might be possibly because i haven't been driving it correctly, mentioning that its good to high rev it so it wouldnt build up carbon. I don't think that is something that would affect my car going idle.

So i'm thinking that wednesday i'll take it to the dealer and do a compression test.

I just recently purchased the car about 3 months ago. So the previous driver hasn't mentioned when he replaced coils,plugs etc.

RIWWP

iTrader: (2)

Excessive carbon from too much low RPM driving can cause idle problems...easily.

Reason:
Any compression related problems are made worse by lower compression, as our compression rate increases more as you turn more RPMs. Overall compression ability dropping starts manifesting on hot start, then idle, as it's the lowest RPM with the worst 'natural' compression rate. Excessive carboning in the leading cause of compression failure in our engines, as the carbon caking on the housing keeps the seals from laying evenly or the seal springs get carbon fouling them. Both issues lead to uneven seal wear, as well as causing short term compression problems.


Do a decarb / seafoam before bringing it in, to see if that improves anything.

An unknown history on the ignition also makes that suspect as well, as weakening compression can make it harder and harder to properly fire a mixture at low RPM (or unable to keep up with high RPM frequency), so a poor ignition can just exagerate the problem further.

VRExile

I know this is a pretty newb question but how would i go to do a decarb/seafoam?
Yeah i'll try to get as much information on the ignition, he mentioned he never had a problem like this ever, mainly because when he did have it, he'd only drive it for about once every 2 weeks.

RunawayRotor

So all of this is happening with no CEL popping up??
If its coils, plugs, wires, or ESS...a CEL should be lit for misfire.
Kinda sounds like a vaccum leak...idles ok when cold due to the increased engine rpm and auto choke. When warm and rpm is lower and engine vaccum is lower it falls on its face.
With out seeing or hearing it...just my 2 cents

RedBandit

I was jus curious if anyone has had any problems with a gas line popping off before? The day before yesterday i installed a k&n drop in air filter I left to go to the store yesterday and got halfway out of my driveway then...the car just shut off...I am also a new owner of a 2004 rx8 6speed, so i felt around and the high pressure gas line had popped off (i believe thats what it was) took an hour to get back on. I just wanted to know if anyone else has had this issue so i can fix it, because i dont want to be going somewhere and my 8 burn to the ground.

RIWWP

iTrader: (2)

Um, yes, this is an unfortunately common problem after engine replacements. Once that fuel line is removed it MUST be replaced, as the connector weakens and can no longer grip the port correctly or strongly enough.

We have had far too many RX-8s burn up from this line popping off after engine replacement. No deaths yet, but many many close calls.

Get it replaced ASAP!

Flashwing

Ignorance of how these components work will lead to the fuel line popping off.

If you use the connectors properly, there is no need for replacement.

RIWWP

iTrader: (2)

If his has already popped off, it's a bit too late for that?

RedBandit

Thanks for the information, I was afraid someone was gonna tell me that. The sad part is everything under the hood is brand new. I believe it wasnt installed properly to begin with, because after I put it back on I tugged on it hard, and it didn`t budge. Im checking it very frequently until I can get a new one

nycgps

iTrader: (1)

most don't use them properly.

the line is cheap anyway(especially when you compare to the risk involve)

When it comes to playing around the fuel system, I always replace them all.

I replaced all the lines in my FC even when it looks fairly new, and it's not even using quick connectors. better be safe than sorry.