Missing at high rpm and acceleration?
 

Hey guys, I've done some troubleshooting/replacing parts/searching and I haven't been able to completely eliminate my issue. I'm hoping you guys can give me some other ideas. My nearest dealership is about a 2hr drive so I'd like to avoid that trip if possible.

I have a 2004 manual with about 50K miles on it. I premix and change oil every 3K or so, only use 91 fuel, and red line fairly often. I've had it about 14 months and it had 2 owners before me. I'm not sure how they treated it. The chick I bought it from took it to the dealership in Wichita KS for all the service work.

Normally when I go to pass someone I drop it into 3rd and floor it just for fun. A few months ago when ever I did that the engine would start missing. I can usually find a point if I back off the acceleration where it stops missing. This usually happens if I've driven for longer than 30min or so. If I only drive for 15min to warm it up I can go all the way to fuel cutoff at WOT with no problems.

As per the other threads w/ similar issues I've replaced the plugs, wires, coils, and reset with the break pedal trick. I've never seen the cat glowing, but that doesn't prove it's good. My cel is on and I'm 90% sure its for the back o2 sensor. The problems start about 6000rpm but below that it runs fine and idle seems to be ok.

After replacing the coils it is quite a bit better but I can still feel it missing under the same conditions. I have been able to get it up to red line after finding the amount of acceleration where it stops missing.

I'm not sure if seafoam or mazda engine cleaner would help, but probably wouldn't hurt. The air filter is a little dirty but I'm guessing it's not the culprit. It wouldn't surprise me if it was the cat. Or are these issues that point to an engine replacement? A trip to the dealership would obviously be necessary.

I've reached the end of the rx8 knowledge that I've gleaned from this forum. My dad used to own an rx3 back in the day so he familiar w/ the rotary but there have been a few changes since then.

I would add a can of seafoam to half a tank of gas and drive as usual. See what that does for you.

As long as Seafoam removes water. Otherwise add Heet too.

Check for intake leaks.

If you have an aftermarket AF then check the plug under the Tb to make sure it is sealed.

If they don't work, I'm sure someone is going to recomend a fuel pump change.

Have you brought it to autozone or somewhere to read the code. That should tell you what's wrong.

Thanks for the replies. I'll try the seafoam and maybe heat. When I get a chance I'll have it scanned and check out the intake.

if you dont have a cel code you are just pissing in the wind..


it is that simple.

beers :beer:

Comeon... atleast you could say something enlightening :)

Finally an OP who is pretty educated and thought of many of the problems that might have occured...

The only thing I could go for is mainly the CAT or the Fuel pump, worst comes to worst, you replace the engine. (Hurray for 8 year warranty!!)

i could write 15 to 20 things it could be.

but the cel would answer the question right away. so why check or replace a bunch of stuff for not reason..

waste of time..

my guess is a 420 code.

but it could be a

loose plug wire
loose plug
loose coil connector
bad coil
bad plug or plugs.

or the other big shot is this happened on low fuel and it is the fuel pump.

but the cel would make it easy.. and if it is just a 300 code. i have some odd info for you. :)

beers :beer:

I am having the same probs as the OP, I recently did the LS2 coil upgrade. I had thought I might have screwed up the wiring but after careful testing of all connections I am certain this is not the case. I thought maybe I had fouled out the new set of plugs I installed when I did the swap, but that is not the case. I have had some problems with my fuel pump though, on a recent trip to TX, about 17 hrs into my trip my my fuel pump literally shut off and cut the motor off. After a couple minutes of sitting on the side of the road I started it up and pulled into the nearest gas station and filled up, continuing on my trip. After about 3 hrs and 3/4 of a tank a fuel the car shut off again. Both instances occurred with less than half a tank.

Ever since this incident I can no longer accelerate under WOT at any RPM. If I'm cruising at 2k in 2nd gear and stomp the gas, all I get is what sounds like a top fuel drag car with a 2 step. I can run up to redline in any gear as long as I only give it half to 3/4 throttle, but only when it's cool outside. I know I need a fuel pump, just can't find the money to take care of it right now. BTW, I'm not throwing any codes other than a random misfire...it does misfire like hell at idle once completely warmed up or if I have run the car for more than 30 minutes.

to funny,

need a new fuel pump? i have one. and two used ones. both modified..

the oldest one used to do what yours is doing. it does not anymore..

and will go to .5 before fuel cut in the left hand turns.. :)

beers :beer:

Did it do the Kessel Run in less than 12 parsecs?

A Parsec is a measure of distance. Not time.

1 Parsec = 3.08568025 × 1016 meters or 3.26 light years.

sorry,

to clarify. that is .5 of a tank. for those that have fought this issue it is kinda known..

btw, good job al. i did not have that math covered..


beers :beer:

The Kessel Run is an 18 parsec route. Solo was not referring to time taken; it was implied that by making it in 12, he took significant shortcuts to do so.

wow,

nerd crapping? how timely! :lol:

beers :beer:

nErD!!!http://i409.photobucket.com/albums/p...g?t=1240207667

I am not ashamed. :lol:

You may proceed with your regularly scheduled programming.

Yeah man, I do. Did you get my pm I sent you last week about the pumps? I'll send it again.

Nic

HAY! Stop posting my picture on the net or start giving me royalties.

Mu ha ha...

The "this thread is worthless w/o cel codes" comments will have to wait till I can make it home to see my dad. My local parts store doesn't have the equipment. I may see if the shops around here would charge me anything.

After driving about 30min I stopped to add the seafoam and topped off the tank. It was about .5 full. I decided to take it out on the local interstate to see if the full tank did anything. It worked perfectly for a while, dead stop to redline through 3rd wot 3-4 times. Took it home checked the oil and added a little and took it out again to pick up some stuff. It started acting up again and the cel started flashing.

I have have a job 30min away tomorrow so I'll see what happens.

If you are interested I am selling my datalogger and code reader here:https://www.rx8club.com/rx-8-parts-sale-wanted-44/fs-can-datalogger-autoenginuity-171844/

It will pull all your codes as well as read all your sensors.

Ok, I ran my dad's scanner on it and it had 3 codes.

P0037
P0302p
P0037p

From the info w/ his scanner those are misfire (302) and O2 (37) sensor problems. Feel free to correct me if I'm wrong. I also cleared the codes and on my trip back home passed some one and earned a blinking cell for my efforts. It didn't stay on though. Fuel tank is at what I've always assumed if the 3/4 full mark, or .75 for swoope :).

Sounds like you have a bad O2 sensor then. I suspect you should replace that first and see if the misfiring continues.

Al: If familiar with a parsec is and it's usage as quoted is appropriate to Swoope's comment due to the ambiguity of both quotes and implied understanding of the audience. :)

you are killing me! :lol:

if i sell some stuff this weekend i will buy your scanner.

usb, works with vista?

and to op.

the 302 code is rear rotor miss fire.

the 37 is this. P0037 Rear HO2S heater control circuit low ON 2 HO2S heater ´
(See DTC P0037 )

could they be related, likely.

beers :beer:

Are you selling your cup holder?

I'll buy it! :beer05: