WOT = Engine dies.
 

So I've got a weird problem. My Rx8 has been trouble free for a couple years, aside from a flooding here and there (blame my parents for moving the car and parking it right away).

So I store the car during the winters. This past winter, I had to get my car towed to where I keep it, because I had a blown tire. I put in fuel stabilizer in, but only had a quarter of a tank (couldn't fill up more, since it was on a flatbed : c)


Fast forward to a couple days ago: I opened the garage, and hopped in. Tried to fire it up, and it didn't want to take. Immediately did the deflood procedure (to save from just flooding it any more than it was) engine started up. A little grumpy, but no different from before. At this point, it idles until temp is up. So I take it for a spin. Drives okay so far. Take a right on to the main road to stretch it's legs. And..

At 5k rpm at full throttle it hesitates hard. I.E. like the fuel is cut off. and it stumbles, and won't really go any higher. I turn around, because I had a feeling, maybe I had a flat, and the rim was spinning, and the traction control was coming on (don't ask me how I know that : c).

I had to drive an hour to get the car home, and so long as I kept the revs low, the car drive 100% like normal. Until I got the car home...

So I tried to give the car one more WOT the next day. Maybe it cleared itself up? Nah.

Anyway, so WOT does the same thing. No powers. Sad faces all around. HOWEVER. New thing happened. No engine light again, but the car loses power completely. It's like the fuel rail was disconnected. Or the fuse removed. Think of a car out of gas/motorcycle when you have to switch to reserve. So I put my four ways on and stop. Start the car up again and it won't idle at all. So at stops I have to blip the throttle to keep the engine alive. It has since figured out how to idle, but the WOT problem is still happening.

I'm going to take it into Mazda next week, but I'd like some opinions of what's going on.


TL;DR:
Car taken out of storage. Fuel stabilizer used, but i filled up to a full tank.
Car won't rev AT ALL past 6k without a lack of power/feels like fuel is cut.
At some point it decided idling wasn't cool anymore.
Got it's idle back, but still refuses to rev high like a real car.
When it loses power from a high rev, it will NOT rev until the car is restarted.

Some things to check:
- Check for rodents or rodent damage. It was in storage, and there are plenty of stories of rodents nesting in the engine bay
- Sudden engine shut down while it's driving is usually a failing fuel pump. In case this is true, do NOT go WOT. A fuel pump failure while WOT can cause a sudden lean spike that destroys the engine. Yes, several examples of that too.
- Something is clogging the fuel filter or fuel line. Won't let more than X volume past, and you need more fuel under WOT than it can deliver. Same warning about WOT
- Grounding points. Perhaps a critical ground corroded too far, and under WOT it is jumping free and killing the electrical circuit to one or more components (could be anything, depending on which ground)

Bad cat, clogged

Take the cat off, if the hony comb is not in place then those pieces are stuck in your exhaust. But since you said the car was running fine before you stored it, I bet some rodents made a nest in your muffler and clogged it.

No, I disagree with that. (Friendly disagreement of course)

A clogged exhaust will cause a restriction, but not cause it to suddenly shut down during WOT. It's a choking that throttles back the power more and more, over a graduated scale. No exhaust clog will cause the engine to just abruptly shut down.

Sure it will, I just went through this last week. If the motor can't breath , it chokes and then dies. A failing fuel pump will have the same symptoms as well, but a fail ing fuel pump will fail all the time , at idle, cruising, WOT. Which leads me to believe its a bad cat or clogged exhaust. After I replaced the muffler with a cat -back sysetm my car is back to normal.

The other thread you posted this same solution in IS failing at cruise.

I had a severely clogged cat, full throttle in 2nd gear barely could get me to 50mph. It wouldn't be driveable period if it's clogged enough to cause a full engine shut down. The engine is still compressing the exhaust (in the engine and in the exhaust) trying to push it through, so there will always be some level of rotation available. Even if the clog is that severe, it's not suddenly going to clear up all by itself by pulling to the side of the road and immediately restarting, allowing you to drive normal, or allow you to drive at cruise completely normal. The clog is there 100% of the time. If it's only a partial clog that is allowing full evacuation of exhaust at cruise, then WOT power is just going to be restricted to that limit. It's not going to suddenly increase the clog and shut down the engine. That simply doesn't fit the description here, or in the other thread.

So it was still doing 'it' and I got my second tank of gas. I went to the fusebox, where I noticed that the 20amp fuse for the heated seats was down one spot (I think it was on foglights or something) I moved it to it's proper spot, and then pressed my thumb on any fuse I could see, including the fuel pump one.

Look like the problem went away. Did it go away for good? I don't know. I'll be taking this into mazda for a compression check. Hopefully I'm still in the warranty zone. That's unrelated though (I think my rx8 could make a bit more power, aka low compression)