Midrange Rpm Brick wall (searched)
 

Hey Guys, I purchased my first 8 about two weeks ago. I've owned numerous Rx-7's so i'm familiar enough with a rotary.


Today was the first time I was able to drive the car, as I just got the tag in.

I was on my way to get the plugs changed, and i noticed at WOT between the middle third of the RPM range, the car just feels like it stops pulling, then suddenly will surge ahead. I changed the plugs (old ones were complete garbage) and still have the same issue.

So next thing im thinking is, okay..coils or cat. My question about the cat is, I remember seeing a post on here while searching that one member had the carpet burnt on his passenger floorboard near the seat because of a clogged cat.

So I figured to myself, okay, let me feel there and see if it was hot. I wasnt driving the car exceptionally hard before I touched the seat rail in that area of the passengers floorboard, but the rail was what i would call warm (could only hold my hand on it for about 12 seconds.)

I know this is a weird question, but based in my interpretation of the heat down there, do you guys think that is enough evidence to suggest the cat is on its way out and I should order a midpipe?

That's not really saying anything, to check the cat properly , see if it's glowing after a good drive (under the car) or take it off and inspect the honeycomb inside. I would be surprised though, you say it pulls ahead beyond a certain RPM.

For the coils, when was the last time they were changed?

Any check engine light? at what RPM does the wall start and end?

I just bought the car eleven days ago from a dealer, so I cant technically say when the coils were changed. The car has 101k on it, and the dealer 'claims' the new motor he put in had 50k on it.

No CEL that I can see. unless the dealer tried to hide it and unplugged the CEL from the cluster? (idk if thats possible, but I'm just speculating.)

I've read about checking it after a good drive, but I don't want to drive the car hard if the cat may be the problem. If memory serves, the wall stars and ends between 4-6.5k

Hey have you found a solution to this, I'm experiencing it with my 8 right now. I would like to get it resolved before a trip I plan to go on with it.

Hi 2014! I highly doubt he'll respond. He may not even have his RX-8 anymore.

Test the three solenoids mounted to the back of the UIM. They can leak causing the vacuum reservoir to empty and not be able to actuate the SSV and/or VDI.

Pull the UIM, pull the three solenoids, draw vacuum on port "A" (see bottom of page at link below). They should be able to hold 10 psi for a while. Then, while you still have vacuum on that port, apply 12V across the pins. The vacuum should go away. If either of these don't happen (doesn't hold vacuum or solenoid doesn't activate) replaced that solenoid.

SECONDARY AIR INJECTION (AIR) SOLENOID VALVE INSPECTION

Replacement solenoids. They're cheap knock-offs and I've had 1 crib death but two more have lasted for a couple of years.

Hey Not,

I just replaced those less than a year ago when I got my engine rebuilt. Also it only happens while I'm driving if I try to accelerate around 3-4k, then the weird wall goes away after around 5-6k. If I go WOT from first all the way through the gears I don't have that issue.

Still sounds like the SSV. 3500 to 5700 is the range where it's active. Perhaps not the solenoid but the valve itself or the vacuum source.

Hey loki,
ill check that out and I'll let you all know thanks.

I had this problem when I had my racing beat intake. When it would heat up, the rubber would soften, and the clamps wouldn't hold it in place. When I would accelerate, a gap would open up and create a vacuum leak.

Switched back to oem intake and all was well.

The point of the story is: keep checking for vacuum leaks.

Hey Loki,
wasn't the solenoids. Just replaced now and I still have that same problem. Let my try to explain it better.

Cruzing in a higher gear at low rpms, if I go to floor it or accelerate a little bit the rpms shoot up but the car doesn't have any umph.

If I'm going hard off the line WOT there's no issues, even shifting in-between gears.

Archwisp,

​​​​​​I'll look into doing one if those diy smoke test and see if I have any. Thanks

Auto or manual? Sounds like a transmission issue to me.

Maybe your clutch is slipping if it's a manual? Do you smell anything?

6-speed manual. And when I pull the ebrake up and start going in first or even reverse the clutch doesn't slip. I've felt a slipping clutch once so know the feeling. And it doesn't really feel like that. No strange smells, no smoke either

If the rpms increase without a corresponding change in speed, your clutch is slipping. There is no other possible explanation, a working clutch requires the wheels to turn at the predermined speed for rpm and gear.

The test for clutch slip is usually done in a high gear, not first.

Hmm I see, I'll be trying that out now. Just curious would I be able to do a during burnout even with the clutch slipping this much??

Alright and the results are slippy clutch, what's sucks is that I literally just put that guy in like a year ago. So now j play the waiting game and order anew clutch, then install it. I'll let you guys know if I still have the same priblem.

if this is your usual clutch release.... you will likely need to get good at diagnosing clutch and drivetrain issues.... 😉

Haha it isn't, although I did find it interesting how the slipping was only in the middle but starting up and doing burnies have been fine, parking on my hill was a bitch though, almost hit the neighbors trashcans

Fixed.
 

So I was the clutch, I had the exedy stage 1 clutch and honestly it only lasted 10k weren't back to the stock exedy clutch and the pedal feels a little stiffer, i.e the pressure plate, and it is easier to party on my hill now with our burning the clutch to much. Thanks all!!

Did you have the stage I or Stage I HD? The HD was discontinued and replaced with an RX-8 specific stage 1 clutch (the HD previously sold was the same kit for the the S5 Turbo II RX-7, but a lot of people had issues with it slipping, hence why they probably stopped offering it on the RX-8 and have the RX-8 specific clutch kit now.)

I'm not sure, I bought it from exedy Amazon page and it came from exedys. But don't know if it was the HD or not. Though I bought the OEM rx8 clutch and now that I can compare the both back to back with out forgetting how it felt, the OEM pressure plate is stiffer but over all the felt better. Also the box and package was nicer like it was specific for the 8.