I went for a fast trip down the motorway last week and lost power to the point where I had to drive with the hazards on.
Drove fine until I tried to reproduce the problem.
Driving at 6-7k rpm for about 10 minutes today. Got CEL for about 1 minute when leaving the motorway. Started getting the power loss again but this time it eventually cut out when idling at a junction.
Got it started after leaving it for a while, then it died again around the corner.

It's always had a rough idle so I think maybe the engine mounts could be contributing to the problem.
It's an 04 RX8 with 89k miles.

Any ideas would be appreciated


I had a good thumb through the threads and didn't see any posts which were quite the same problem.

 

And none of the threads you "thumbed through" mentioned spark plugs, coils, cat, or getting the CEL read to know for sure what the code is for?

When was the last time you changed your plugs and coils.
Have you ever had the cat replaced?
Like I mentioned... you can take the car up to the local Autozone and get the code read for free.

 

It only happened a few hours ago so I can't check some stuff in the dark.
Coils and plugs were replaced 6 months ago
Cat was replaced in 2006
Don't have local autozone's over here. Or any garage that would do anything for free

 

I'd lay money that it is one of the following:

A) Your coils are shot (30,000 mile life on them)
B) Your plugs are shot (30,000 mile life on them, can fail if your coils do)
C) Your cat is shot (life depends on how often the above fail, them failing accelerates it, although even if they are perfect it might not last to the 80k warranty)


Edit:
The 30k lifespans are general max. You can get them to last longer if your lucky, and they certainly can fail earlier. Though 30k is typical. My first set failed at 35k, my 2nd failed after 16k and blew my plugs and cat along with it.

 

I should have guessed that by the "Motorway" reference

Were all the plugs and coils replaced 6 months ago?
Might want to verify none of the spark plug wires came loose.
With the cat being replaced in '06, roughly how many miles are on it?

 

Crap.......didn't see it in time! Was gonna point out the use of that term Jon.........he's in Dublin, Ireland!

 

I read a lot of similar threads but I didn't notice people cutting out completely.

lol @ motorway

 

Yes, it can and does happen. It usually is when you return to an idle condition, like at a stop light or something of that nature.
Get that code read somehow! If your lucky, it hasn't taken out the CAT yet!

 

Its all good... only other time I hear the Motorway reference is the voice coming from my TomTom

 

It's a sad day when someone in a Skoda laughs at you broken down at a junction

 

Not too damn often you slip up and was gonna get ya back for the APV vs. SSV mistake I made last night!

 

I'm sure you'll still have an opportunity

 

^...............suck!

Don't worry, you get it...........start easy and work your way to the more difficult.
I would change plugs(maybe the wires), the coils for sure, and at least pull the front of the CAT loose and take a look in there to see if the honeycomb is still in place or whether or not it's all in pieces(that would be bad). But.............ya really need to get that code read as soon as possible!

 

Good advice.
Think I'll bring it to the garage this time. I need to get the mounts changed anyway.
I'm a pretty new RX8'er. Should I look into buying my own code reading device?

 

In my opinion................that answer would be yes, without a doubt. It has to be able to CANBUS compatible. There are cheaper ones and of course more expensive ones, but I first had a scangauge.......... www.scangauge.com and it would do what you need and more. Reads and clears codes, plus a lot more. Free shipping right now..............wonder if that means to Ireland! I doubt it!
My old scangauge is now on my daughters Mazda 3 as I have something else.

Good thing about that scangauge is you can easily move it between cars and works just about every car since 1996.

 

Good stuff. Think I'll do that.

My 8 was in for our National Car Test today. Failed the emissions test but apparently rotary engine are exempt from the emissions test, so overall it passed.

 

Sounds like you went into limp mode.
Maybe the coils or a coil overheated cause its old.
You shouldn't be going into limp mode at that RPM.
Butt... you didn't tell us if you were driving in a straight line or if the motorway had some good curves.

If your at 1/4 tank of petrol... the RX can get fuel starvation around a corner.

Also, a major misfire or major spinning of the tires will cause the ECU to think you are in trouble. Then it will go into limp mode.
This will put you in limp mode not the RPM.

 

It was a good 10 miles of straight good grip road.
3/4 of a full tank.

 

Dealer said:
2 coils are gone
2 sparks need to be replaced
A vacuum line is busted
And they're going to run a can of de-carbon stuff through it to clean the cat.

 

Good to hear its getting fixed and in a minor problem.

I'll drink a Basle Ale for ja.

ah............

 

If that doesn't correct it, I would look at the fuel pump. Mine developed a problem this weekend. It stumbled anytime I tried to accelerate. I added fuel to the gas tank and it started working again for a while. The fuel pump seems to be over heating and adding fresh fuel cooled it down for a while.

 

Went on a 200km drive today. Power delivery was pretty weird. It wasn't there most of the time or took a long time to get there.
Got to a junction, dropped the revs down and they kept going down, and down. Dead at another junction!!!!
€450 euro less cash in my pocket with zero improvement.

 

You might be onto something there.
I stopped for fuel at one point and did notice an significant improvement for a while.

 

Hey davestyle , my car did the same thing in last 3 weeks, stall at the stop sign and misfire engine sign is blinking and stay on, but it all happen in the low rpm not high rpm at all !! so i replaced all spark plugs, IG coils, Wires, engine mounts, now move on to CAT ..... so hopefully it's CAT, pls update if you have any more info

https://www.rx8club.com/ne-rx-8-forum-29/engine-vibrate-almost-shut-down-when-its-low-rpm-189644/page2/

 

I'm going with the pump on my one. But I'll let you know.
She's booked in for Monday so we'll see.