frustrating problem i need help
 

hello im new here i cant start a thread so mine a MT 6 speed 2005 model. my car start up and idle normally but when i accelerate my car shakes it make a strange sound like fluktuating. i got car on check up change ignition coil and spark plugs. no error on obd scanner even checked for a vacum leak. the car has been decat. i dont really know where the problem is. plz help

frustrating problem i need help
 

hello im new here i cant start a thread so mine a MT 6 speed 2005 model. my car start up and idle normally but when i accelerate my car shakes it make a strange sound like fluktuating. i got car on check up change ignition coil and spark plugs. no error on obd scanner even checked for a vacum leak. the car has been decat. i dont really know where the problem is. plz help

Yeah?
 

what do u mean reset the ecu???

how old is your fuel pump?

Just wanted to chime in here as my AT '05 just developed this issue. I think I have a good idea of what's going on but it would be good to have a sanity check from others who have more experience/knowledge. (Thanks a lot to everyone who's already contributed to this thread).

I just finished up replacing the oil cooler hoses with the kit from Banzai Racing. It needed a jump the first time, most likely just from sitting for several weeks. I had taken it to a shop at first but they wanted ~$1200 to replace the corroded hoses. Anyway, they flooded it and I'm guessing they drained the battery trying to get it going again. They jumped me at the time and I drove it a couple times before settling on working on it at my parents' place. It seemed fine in between. After a few weeks of not being driven I finally got the work done on the oil hoses.

Went for a drive around the neighborhood and to refill gas and I noticed the rough idle at stop lights. RPMs were steady at anything above 1500-2000. Started fine at the gas station. Brought it to my parents' again, let it cool, and then went to start it again. Again, started fine, but after idling a few minutes at the normal 750 or 800 it started dipping and recovering again, like it was trying to compensate, and then eventually stalled and died. I was able to restart it immediately but after another minute it struggled then died again. I decided to be brave/stupid and drove it 30 minutes home. Started fine, but again got close to dying anytime I stopped. BUT after revving it higher on the highway and finally parking it at home, it was able to idle steadily for a good 10-15 minutes.

Now I'm here reading this entire thread. :)

Sounds like I may be lucky and it's just the fuel trims readjusting, especially if it seems like it's "getting better" over time. While I was working on the oil hoses I also replaced sparks, coils, and leads (all NGK), and had the battery disconnected through the whole procedure.

Full disclosure I do have a CEL but the only codes are for the secondary air pump, which I understand doesn't affect the functionality of the engine besides for emissions? I know for sure my air pump is broken but it's been perfectly driveable otherwise since before this most recent project. That's still first on my list if things don't level out on their own.

Next up would be cleaning MAF and ESS, and then do the brake stomp reset.

I also saw the recommendation of getting a wireless ODB2 with realtime reading capabilities, that sounds like a good thing to have regardless.

^ Sounds to me like you are on the right track.... I'll give you some confirmation on the sanity check. If idle does not improve over the next few drive cycles then I'd begin looking over your ignition changes, make sure spark plugs are in tight and all leads are on the proper plug/coil. The brake stomp reset and cleaning MAF/ESS is a good idea regarless; same goes for the OBDII, the more info you have at hand the easier it is to diagnose issues.

Thanks, appreciate the vote of confidence. Over the past few drive cycles it does seem to have evened out, but it still wavers occasionally, just enough for me to worry about it. It hasn't stalled out again at all, but I've gone ahead and ordered MAF sensor cleaner and a live data ODB2 scanner anyway.

mine does the same thing and I even changed the spark plug and wires and dedlooded the engine and it runs now but dies at idle after 3 seconds. Can anyone help us out.
I also replaced my MAF SENSOR as well. Anyone know what's going on??

Have you replaced the ignition coils recently?
Can you keep it running by feathering the throttle?
See if works better with the baro sensor unplugged.

No idle
 

Im new here so I couldn’t make my own post but this one seemed the most relevant to my issue.

I recently purchased an 04 rx8 street ported, the body has almost 120,000km while the engine was rebuilt at 60,000.

The only way to start it is to give it a little bit of throttle and it starts up right away, once started unless I keep giving throttle it drops rpm’s all the way down and stalls.

ive replaced spark plugs, wires, coils and have cleaned both the Ess and maf sensors. I have also tried all the reset methods and I still can’t get it to idle.

I’ve tried taking it for a spin but when I put it into gear it drops rpm and moves for a couple seconds at really low rpm’s and stalls out.

the codes I have are P0076: intake valve control circuit low, P0302 cylinder 2 misfire and P0037: h2os heater control cuir cuit low voltage (which I think is from the decat)

if anyone could help me with this it would be appreciated thanks
https://cimg6.ibsrv.net/gimg/www.rx8...f9795279a.jpeg
https://cimg7.ibsrv.net/gimg/www.rx8...4918bb96d.jpeg

No idle
 

I’m new here so I wasn’t able to start my own thread but this one seemed the most relevant.

I own an 04 rx8 streetported with a cold air intake. It’s been sitting for 6 months and I can’t get it to idle, it only starts up when I give it about 1/4 throttle when cranking, I’ve had it hold idle for about a minute or two before it died out by trying to keep the throttle around 1500. It starts up right away when I do the throttle thing though which makes me think it’s not low compression. I had my friend start it and when I heard the engine there was kind of a hissing noise which makes me think it’s a vacuum leak, could that be a possibility? Would anyone be able to help me with this?

Thanks

If you are seeking for some help, post in the New Member section or thie thread next time:
https://www.rx8club.com/rx-8-discuss...8/#post4964832
VFAD not capped is likely the source of the hissing noise.
This can't be called as an Intake nor cold air intake. I guess beside the fact that this is a hot air intake, it does not have the screens to straighten airflow. Get a used stock intake, the stock intake is very good, only AEM, MS or RB intake can outperform the stock one.
Use this manual and follow factory diagnostic procedure.
M A Z D A

P0076 is VDI solenoid valve control circuit low
P0302 Rotor 2 misfire, swap the ignition coil wire and spark plug with the rotor No.1 to see if it becomes P0301.
P0037 is for rear O2, you can ignore this for now.

Vacuum line diagram.
https://www.rx8club.com/series-i-tec...iagram-214910/

Out of ideas.. Fresh perspective needed please.
 

Hi All,

This will be my first post and I could not make a fresh thread for some reason, therefore, I am placing this into a "reply" here.

I purchased a 2008 Rx-8 Manual Grand touring with 98000Km.
- Compression is good
- Coils, Plugs, Wires, both 02 sensors and MAF swapped with new OEM
- CAT looks OK
- EGR taken apart and cleaned (working)

Before changing out the new components the car was getting a multitude of codes. After replacing everything, the codes went away except for the cylinder 2 misfire. The car was running and idling perfectly through all power ranges, it was puuuring with a nice clean exhaust expulsion ..... I did the 20 break pedal stomp and the misfire code cleared. NOW, the problems start.

After the break stomp, my car will start and idle fine when cold. I can hear the CAT air pump running and shutting off as it should. After the car warms up, it will idle up and down and then just idle down to a stall. It even sounds more grumbly and emits a bluish exhaust smoke after the break stomp.....

I put the old MAF sensor in I instantly get a "fuel rich" code with backfires. So, back goes the new Denso MAF still with issues stated above. And zero codes.

I disconnected the battery for a while, no change......Cleaned the TB, no change

I did a smoke test and did not find any vacuum leaks. I've been reading about the fuel trims needing to relearn, but the current state of how the car is running after the break stomp seems to be a little drastic.

Any ideas? I'm at a loss now..... I haven't cleaned the crank shaft sensor since I haven't been able to find a link to do so, but I will keep searching.

Thanks in advance!

V.

P.S. I should add that there is an aftermarket cold air intake installed. I would love to get my hands on a used stock air box kit. There is a wiring harness that splits off of the MAF wire bundle that is not connected, as circled in the picture (not my engine). I'm not sure what this is for.
https://cimg0.ibsrv.net/gimg/www.rx8...bc44f3fb42.png

You can post your question in this thread or in the new member section.
Factory service manual can be found at Foxed.ca
There's no EGR on our car so I'm not sure what you have taken apart.
The eccentric shaft position sensor is right by the eccentric shaft pulley.
The green connector is for VFAD, (most, probably all) aftermarket intake does not utilize it and it's mainly for sound suppression, you should check to make sure the VFAD vacuum line is capped to prevent vacuum leak.
The only 3 aftermarket intake that will run right is AEM/MS (same) and RB if you have a KN get rid of it, it make you lose power and get a unstable idle because the MAF does not read right. If you have AEM then make sure the mesh screens are properly installed.
I'm not sure if our OE MAF is made by Denso or Mitsubishi someone who knows please chime in.

Thank you for the reply.

What I thought was the EGR is the Air Control Valve. I pulled the ESS and cleaned it, the VFAD is capped, the cold air intake is AEM and screens were checked.

I concluded through process of elimination that the problem must be the the upstream O2 Sensor, so I unplugged it at the harness to put it into loop mode and the car is running and idling as it should now (still a bit of blue exhaust though). I guess I will have to return the O2 back to Rock Auto and bite the $329.00 CAD for an upgraded part, unless someone knows of a less expensive O2 sensor that is proven to work with the X8.

Thanks again,

V.

Use only OE O2 and MAF sensor, people have tried afterarkets one and they do not work.
Our O2 is a wideband so that's why they are expensive. You can visit Mazmart's website for OE part.

NGK 25673 Bank 1 sensor 1
 

From what I can see, the NGK/NTK 25673 should be the correct sensor, but on the supplier website is says that it is a narrow band! Perhaps just an error on their site, but NGK doesn't specify the band on their website.

https://www.napacanada.com/en/p/NGK2...pressionRank=2

Can someone confirm please?

Thanks,

V.

It says narrow band but the description says it measures AFR of 10 - 18

Also it uses constant V and current measurement.

Looks like it's the correct one

Awesome, thanks!

Same issue
 

Well, still having the same issue. Put the new sensor into bank 1 and cough cough cough sputter stall..... Unplug the sensor and she's good. :(

Crank but no start.
 

Can anyone help me out? I’m located in the phoenix valley. I have a 2006 Mazda rx8, and I’ve tried the deflooding process three times and I still haven’t gotten anything. I’m not super experienced with cars, and I’m in a bit of a financial situation. I just need my car back so I can get a job again. If anyone can help, please let me know. I’m starting to lose hope.

I have an RX8 also. The rotor compression weakens over time causing this issue but dont be alarmed. Its not much different than the compression rings slowly wearing and weakening compression around a piston. The fuel trims are very tuned factory and can't compensate for this. You can't trick the system electronically either. The fix for another 100,000 miles or so is simply removing the accordion horn on the intake and opening the brass butterfly with your fingers then grabbing the bottom of the butterfly with small pliers (you'll notice an almost complete circle where the brass is pressed around a thinner layer where other models have a breather hole but this model does not) gently bend the thinner bottom section of the brass circle approximately 1/32 to 1/16 forward (towards you) this will allow a higher volume of air flow to enter the intake forcing the control unit to allow more fuel therefore increasing your idle. You can adjust it more open or closed depending on your needs for idle. People will more than likely caution you against doing this due their trolling nature but this is your only option unless you prefer to rebuild your rotary engine every 50,000 miles to keep compression up. The fuel trims will be off a minute amount due to increased air volume but they will adjust a small amount to compensate and you will be very happy you tried this. You should be able to get around 260,000 miles give or take on each rebuild with this mechanical modification. Just be sure to change oil every 2500 to 3000 miles. The oil is the life of these types of engines. They cannot handle the abuse or neglect that a piston engine can. The only compression they have is between the apex points of the triangle rotors and the apex seals. Once these wear the compression will be gradually reduced with every mile. Wipe around the brass butterfly afterwards to remove any debris you may have made and reinstall everything as you removed it. No need for a reset or any of that annoying stuff. The trims aren't far out enough to make a difference. As you drive it will adjust the trims as tight to idle and operating rpms as the computer has the ability to. You will more than likely get a check engine light after awhile and when you read it with your scan tool it will inform you that idle is too high. Accept that as a badge of accomplishment and drive it until you need a new engine, your next rebuild, or a different vehicle. Welcome to the rotary engine world. Note: be sure to modify to make idle high enough to compensate for air conditioner pull down and alternator pull down as this cause a dramatic drop in rpm when they engage. I have found success in adjusting the airflow to allow a 1,275 rpm idle and when they engage the pull down never drops below 950 rpms so there is no engine stalling at red lights. If you open too far you will get a high surging idle as the computer is trying to correct it. Simply reduce your gap a little at a time if this occurs until you reach the rpm you are happy with. Good luck.

So screwing up the throttle body should work :sad:.... the drill a hole Idea is easier to reverse so if you insist do that...

Danobre, it is sad but its either that or leave these poor folks stalling at redlights. It's safe. Also it's 50 cents worth of brass. You're not screwing up the intake lol. The brass can be removed and replaced very easily. But if you were to screw up an intake on one of these who cares. They are short life cars. They are basically valueless. They are just fun to drive.