I built the engine.
Yes it was in and out at least 20 times :D


So now back to the problem:
I tested all selenoids all were ok. The cup i was speaking about is actually only silencer.

What was causing all the problems was the check valve on hose connecting intake to vacuum chamber.

It looks like the secondary intake port were only half open that was causing the strange power disapperence.

Finally after nearly 2 years searching web, forums, testing all sensors and going trough 2 engines .... Now everything works as should.

 

you the man - thanks for sharing!! it's great when folks post their solutions. enjoy your great running RX8!

 

When i read, i have focus 2 problem, 1st. SSV and 2st. Coils. Check SSV and VDI valve actuator membrane. If membrane leaks, It can open late.
And i know. My English is very bad :D

Sorry again. It is already solved. I didnt read second page. Thanks for sharing.

 

I for some reason can't post my own thread, so i figured id just post here.

My 8 seems to intermittently have low power above 5-6k. And i mean intermittently like different starts. Sometimes it starts up and it seems like i have new car almost, other times ill have trouble hitting the redline in third. I just replaced coils, and plugs a few thousand before that. theres about 10k on the brand new engine. It seems to have happened after destroying my front splitter. It was cracked before and i hit something and tore it most of the way off. Could the lack of splitter affect it this much? or just a coincidence?

Any help would be much appreciated

 

Finally fixed powerloss!
At 5000rpm it had a power drop as if it had not enough fuel.
Changed everything coils, leads, plugs etc.
Engine had only 28kmiles.
Then I found a you-tube video about this problem ;the barometric sensor next to the air pump.
You can test it by take the connector off.... The engine light comes on but you can drive it anyway. In my case it runned like hell again.... So I ordered a new sensor en reset the code.
Happy!
Greetings Arnoud (Netherlands}