(help) fire sparks came from the exhaust then engine dead

[seto]

Good day all..

I have a 2004 RX8, 6 speed manual gear with a stock engine. So far only install megan racing exhaust, HKS Superfire plugs, HKS filter and Pivot Throttle controller. Engine in well maintained condition..

This morning I warm up the engine for 5 minutes in 15 degree celsius of winter climate then I start to go for work. After going around 2km suddenly the engine goes off by himself when I stop for signal. Then after i start it again it made a strange noise and engine start to vibrate, feels like something choking and about to explode. I force the engine to keep running coz I'm about to climb a bridge, I though at least I can pass that bridge and stop in the roadside after passed it or else big traffic jamm will happened coz of my RX8. The car start to loosing power and the engine almost shut off when I shift down the gear to gain power then I saw a firesparks came out from the exhaust spreading all over the road just like somebody does a welding/hotworks inside my exhaust. I stop the car then the engine goes off, I try to start but it wont comes.

Two weeks before the incident I start to smell a fresh gasoline came from the engine bay everytime the car running fast in high rpm, but the smell gone when I drive slow or when the car only parking/idle. I check the engine bay, fuel rails and fuel tanks all dry, no symptoms of leakage, then I ignore it even the smell still strong like we are sitting next to a petrol station pump.

One week ago the car start to choking sometimes when we are accelerating. Feels like it having a dirty gasoline or feels like it has a rev limiter. So when it reach particular RPM it will cut off, but it happen in the range of 4000-8000rpm only and not everytime..

This morning that "firesparks" incident happened and I really sad I wonderning what happened with my RX8 though I never missed the service..

Can anyone advice me what happened with my engine? Why there's a firesparks came and then the engine suddenly shut off?

 

[solidtrance]

Thanks for giving us a detailed post to try to help with. I will try to sort through this in my own limited way. I would guess the fuel smell is due to fitment issues with your megan exhaust. I have the AP exhaust and IIRC they are made both made by the same company. I get the same gas smell sometimes when the car is not moving. Did your exhaust come with a mid pipe, cat delete pipe? If not some of the other symptoms could be caused by a clogged cat. The loss of power is common and sometimes a clogged cat can cause enough back pressure to damage the engine. If you still have a cat check to see if it is bad.

I am not familiar with the spark plugs you are using. I would recommend getting a set of OEM standard plugs. Most of the aftermarket plugs are not very good for our car. I am also not familiar with the throttle controller you have. I have experimented with throttle controllers before and I didn't see the point. I installed one on my wife's MS6 to test it for a friend who runs an aftermarket parts business and we both thought it was worthless. It made the car worse.

If you have a cat I would say the sparks were pieces of the mesh from inside the cat caused the sparks you saw. Make sure your exhaust does not have any blockage and you may be good to go. I doubt it, but it is possible. Let us know what you have found out, and how it is going. I hope things work out.

 

[bazooka joe]

sounds like a bigger problem then a leaky exhaust...you best get to the dealer/shop asap...i think i would have brought it in a week or two earlier though! good luck man!

 

[mazdadude]

My first thought is excess fuel caused meltdown of cat. conv., and sparks you saw were from the melting matrix in the cat. as SOLIDTRANCE stated earlier.

 

[Atkins Dan]

Start with a Compression test and see how the engine its self is doing.. next thing GET RID OF THOSE SPARK PLUGS NOW.. Go Put NGK's back in as that alone should change a lot... also when was the last time the coils were even checked or replaced????

Dan