Hi all!
New to the forum, but I've had my RX8 for a while and has been reading all over the place to find a solution. Hopefully someone knows more about this engine than me or my mechanic.
I got a good price on an US-imported (I live in Sweden) RX8 7-8 months ago. I knew the car was running bad but decided to give it a shot as the car was in good condition otherwise. The previous owner told me he had exchanged the engine a couple of years back, but according to him the car was running perfect until he had the front resprayed. After the respray the car was was next to impossible to drive at all, and he said the mechanics who did the respray claim they have nothing to do with it.
Anyways, I took it to my mechanic, turns out the catalytic converter was jammed of old exhaust residues (whatever the respray had to do with that...) and I ordered a new one. After replacing it, the car was finally drivable, but nowhere close to what it's supposed to be like. I changed the spark plugs, the (front, I think) lambda sensor after an OBD-reading claiming it was broken. The car got better and better, but still not perfect. I'd say it feels like it has around 130-150hp instead of the ~238 it's supposed to have. On idle, the car was at 1500 rpm instead of 800, and when the engine got warm (like after driving for a while) it would usually die when stopping the car instead of idling at 800rpm. I still got a bad reading from the front lambda, so I thought it could be the MAF that was broken. Tried cleaning it without success so I bought a new one that arrived today.
It's just a little better, but it still runs like s-it. When revving up from idle, the car goes up-down-up-down-up-down and then finally up before I can drive. As long as I keep it above ~3000rpm it runs fine (but with lacking power). The idle however now stays at around 800 rpm instead of the previous 1500. I just don't know where to go from here...
Another thing that could be of interest, the previous owner had the air filter changed into a K&N which I've heard perhaps isn't the best choice for this car, but I don't have the original air filter box so I can't try to change it back. I've found some sensors of some kind within the engine compartment that I have no clue whatsoever what they're good for, but it looks as if they've been connected. I bought some tube and connected them, but the car runs even worse when connected. Pressing down the gas pedal fully at idle kills the car completely. See the attached pictures.
Please help me if you have any ideas :(
First picture mate is the barometric sensor and should be left as shown no piping attached to the plastic tube. works in conjunstion with the maf sensor air flow.
2 and 3rd are for the VFAD variable fresh air duct( rpm related air duct) as as you have the KnN fitted this has been disable.d so there s no where to plug back in.
Both these above wont cause the issues you have.
Is the engine light flashing? Have you checked the coils and verified leads on correctly . should be from front of car first coil to leading plug bottom 2nd coil trailing 3rd lead rear housing 4th trailing rear housing top.
how old are the coils? This would have killed the cat.
Adding to what Jon has said, this sounds like a vacuum leak.
The pipe that is open was attached to the nipple you will see under the throttle body on the side of the inlet trunk, if this is not blanked off you will have a huge vacuum leak.
Yes Clive i had a typhoon on mine and there was a tube blank fitted over that nipple just behind throtle body. Would this cause the lack of power? Prob a couple of things going on.