Well the story is the following

I am talking about the RX-8 low power manual gear box 5 (Europe Specs).

The problem is that after 5.000rpm there is a hesitation kind of loss of power. You can say that after 5000rpm the engine is having a hard time in order to continue revving and at the same time I can hear a high pitched noise not heard before.

-I started by checking the plugs and actually I changed them with no result (new plugs) .

-Then I checked the Cat that has no problem (visual inspection and also shaking it) and I replaced the cat with another one that a friend lent me just for testing. Again the same problem after having changed the cat (new cat).

-Then I changed the final muffler in the event of something was blocking the exhaust gas for escaping freely but also no luck there again (new final muffler).

-I have checked the compression witch is a little bit bellow spec but this is not the problem. I have driven a lot of RX-8 with marginal compression and they run fine.

-Next thing was to burn the fuel in the event of having bad gas but also no luck again, after having put new gas in the tank again the same problem. (new fuel)

So it remains to change the ignition coils and after that to replace the fuel pump but I am not sure that either of those things might help me.

In addition the dealer cannot find the problem , my warranty has expired anyway to change the engine and I think the only think that I have not mentioned before is that the RX-8 presented the high revs problem after I had given the fuel becks injectors for cleaning and also changed my clutch not to OEM but I have installed clutch/pressure plate/flywheel from RX-7 FC.

So If is is possible from the data given to have a verdict or at least some direction that may lead to solution, I would appreciate a lot.

Thanks

 

How many kms on the car?
What's your oil consumption in kg\km?

It may be a coil related problem or a faulty fuel pump but we need more infos in order to at least point you in the right direction or share some thoughts
Low compression with a worn OMP (or a pcm running on an old flash) may be an added cause of your loss of power as poorly lubricated seals seal even worse.
Have you tried premixing at a higher than usual rate? did this help?

 

The story continues…

I have changed the ignition coils with no success ! And while I was trying to figure out what was the problem I told my friend to rev the car while I was inspecting the SSV and VDI valves.

The problem was found ! SSV and VDI soilenoid valves were not working at all !!!!! So I suspect that something wrong happed when a tech guy from a local rotary shop had my intake removed in order to clean it.

So now I have SSV and VDI not working at all and I do not know how to fix the problem BUT at least I know what is the problem !!! This is a start !

 

What a competent shop!
I have seen locked valves but BROKEN ones... is that a solenoid problem?

 

Sounds like it's to do with this . Perhaps a vac leak or similar .
What exactly was done ?

 

heh - only just read this .

They probably fuxed up the electrical connections when they reinstalled the UIM . You could take it bakc and demand they repair .
Alternatively if you are a diy kinda guy you should learn how to take this off and then check everything was installed properly .
White electrical plug goes to solenoid that controls SSV .

 

Yes I will take it back. Till then you think that they have swapped by mistake the electrical plugs between SSV, VDI and AIR pump ???????

 

Well they have removed the plastic intake manifold in order to have access and remove the fuel injectors that I requested to be cleaned. As a result, after the assembly of plastic intake manifold (and after a lot of my time spent to find the problem) the SSV and VDI were not working.

That is the story.

Anyway I am happy that I found the problem after all and I will be much happier if the rotary shop will repair it.

 

I was right. Back to the rotary shop and one connector (I think it was SSV) was not working. Cutting the wire and Replacing with a new connector made the SSV το work properly.

Anyway happy that is was resolved I was able to troubleshoot the problem without having not a singe DTC from the ECU. ))))))))

 

the Green line connector VDI solenoid valve had a wire detached !