Hello, it is now 2am here in montreal and I just got my car towed... I have a 2005 6 speed GT RX-8. The only mods are; Mazdaspeed cold air intake, catless pipe and that's it!
I was testing my new cold air intake the I just installed 2 days ago and noticed some lag after 8500rpm since day 1, the lag wasn't always present. The last run I did to check if there was a lag after 8500rpm no more power... I had to downshift to accelerate and I was doing 70km/h on the freeway... The symptoms before car dying was: thumping noise from the engine, CEL blinking(probably misfire), CEL staying on(from my catless pipe and maybe other codes), car not accelerating, alot of backfirering and right before I stop the engine coolant light comes on with the battery light and then I realised my car was dead in the middle on the freeway exit... I tried to crank 20 seconds with my foot on the accel pedal then crank to start but it doesn't, it smells like unburnt fuel and it may seem to be more than flooded...
I had my battery and starter changed last year because it would start sometimes and I stressed out my coils from excessive tries to start and I flooded once but deflooded without changing my spark plugs. I already got 2 times misfire CEL blinking at high RPM but it never came back since a couple on month.
So I did some searching and I think I got a flooded engine since I got alot of backfires(more than usual) which means I got unburnt fuel. But why did it flood? I did intense searching on the net while I was in the tow truck and I guess it's the coils and plugs. But why would it do this all of a sudden? Please help me! What do you think it is?

Edit: my car has 143000KM

 

I guessing coils and plugs bro, I recently had a problem with coils they went bad and the car was all messed up I threw a P0171 fault P0113 all kinds of jacked up stuff started happening I thought the car was done change the coils and it was all good new plugs as well. whens the last time you changed your plugs?

 

Hi, first I would like to thank you for reading my post. I got the car at 100 000km and never changed the coils nor the spark plugs. Did ur car stop all of a sudden and didn't want to start?

Edit: UPDATE! I got the car running after pressing on the accel pedal and cranking for 20 seconds. The idle was weird and I got blinking CEL everytime I gave gas... There was unburnt fuel dripping out of my mufflers... Now I turned it off and can't get it started again... Maybe I will try another deflood method...

 

Are you sure that you got the vacuum hoses hooked up right and blocked off the right lines after removing the VFAD? Also, check to see if your accordian tube and MAF are free of oil.

 

Off hand guess is that you have an issue with the MAF setup in your MS CAI. Issue is progressive as the computer is relearning based on bad info coming from the MAF. I'd start diagnosis here if I were you. Make sure the MAF is good (swap with a known good unit for instance). Make sure the wires are connected properly and have continuity (no breaks in wire under the insulator jacket - need a cheap electrical tester and flex the wires a bit to see if they loose continuity). Make sure you have no obsrtuctions and that screens are in place properly in the CAI. Make sure the MAF is seated properly in the CAI.

 

Ok so I will try another MAF sensor on my CAI. I blocked one tube and connected 3 tubes on the CAI any other tubes to connect or block? And u guys don't think it's the coils? Gonna check them tonight! Thx

 

Ok finally I solved the problem! First I checked my coils and they are almost finished, some white spots on them. Then when I wanted to check my plugs I found that one was unplugged... So the rear rotor was not turning well... Now it's perfect except I had to deflood. My plugs are black brown should I change them soon with my coils and wire? And by the way, I just installed the CAI and my car pings around 8400rpm... Like if I had much less torque but I get no misfire codes. Should I put back my stock intake or should I keep my Mazdaspeed intake? Can this problem be fixed? What hose/vacuum leak can cause this? Thx in adv!