New Member/Limp Mode
 

Hi guys, new member here & to be completely honest I have very little knowledge when it comes to rotary engines. So any helpful tips will be greatly appreciated and listened to. I'm also wanting to look for some insight with this thread, I have recently purchased a 2006 Mazda Rx-8. 6 Speed Manual, love the car. However, it's stuck in limp mode the previous owners told me all it needed was a purge valve solenoid, the codes checked out coming back to the purge valve so I went ahead and replaced it. After the installation of the new purge valve, I didn't notice any difference at all, the same issue with major power loss and having acceleration issues. I'd like to add as well that once the purge valve got replaced I had the codes ran once again because the CEL was still on, no codes were stored though. I tried resetting the CEL by disconnecting my battery and waiting a little bit and it would stay off for 10 seconds and come back. The following day I ran some seafoam through the car, after sitting for a little bit I went out for a drive and the car ran properly again. It didn't last long before it was back into limp mode. Today as well I got another good 45 minutes of sound performance, ran excellent. Once I turned the car off to go into the store, it went back into limp mode. Any advice? Thanks in advance!
(Side note, sorry for the long thread.)

More than likely it is a MOP limp mode issue

You can try and move the position switch a bit on the pump to see if it works...

Or buy a used functioning MOP

Since you’re not a rotary mechanic, rather than throw various possible solutions at your car, I’d strongly urge you to visit a Mazda service department or some other professional rotary mechanic.

The time and money you save will offset the cost of having a pro diagnose your car’s problem.

Define limp mode? Normal limp mode is a strict limit of 3000rpm. Power loss through the rev range could have a range of causes from bad coils to stuck intake valves, to incorrectly wired coils.

Does the CEL flash at any point?

Thay said, invisible CEL codes are usually OMP errors like mentioned above. There is actually a code, your reader just can't read it because it's specific to Mazda.

I can generally get up to 3500rpm-4000rpm but that takes incredibly long to reach. 1st gear I can reach about 15 mph then 2nd gear is 26ish mph then 3rd I'm able to hit 35-40. Idling the car won't rev past 4k rmp. I will look into all the info mentioned above, I actually just found out that my car has 3 open recalls so I will have them check it out while it's at the service shop. Thanks!

Is the CEL flashing at all?

Not while running, it has before though. I tried a method I have seen online to reset limp mode and it said to turn your key to the on position but not running and pump your brakes 15-20 times. After doing that the CEL flashed 3 times approximately.

So flashing CEL = misfire, which has a few possible causes, but none of them are great. The one you really want to look out for is failed ignition coils or failed catalytic converter, those will kill your engine quickly. However, given that you have no misfire or cat codes, it's probably *just* your OMP? Stay vigilant with the cat and coils.