Stumble and Blinking CEL @ the Track
 

Hey guys,

I just picked up an '04 with 67xxx miles on it a couple weeks ago and decided it needed to see the track, so I took it out to TWS for some fun yesterday.

Coming out of T2 (a long, relatively fast left hander,) The car cut out and the CEL started blinking. This happened three laps in a row at the exact same part of the track. It's almost like it was having fuel starvation issues, but it had well over 3/4 a tank.

Have any of you guys ever experienced this?

The CEL goes away after a re-start and the car seems to be running fine otherwise.

Other than this, the car was fairly enjoyable on track. It's a bit too soft, and the gearing and brakes kinda suck, but it wasn't bad at all for a stock car.

This is my daily driver, so I don't want to go too crazy with track mods, but I do want to be able to tear up the track whenever possible, so I was thinking about mods for trackability without sacrificing much. Heres my plan so far:

Mazdaspeed track pipe
Mazdaspeed coil overs or springs/shocks
Decent brake pads/new rotors
17'' wheels with 235-40R17 tires to kill the crappy gearing

Any of your input is greatly appreciated! I come from the BMW side of things so maximizing an RX8s performance is a new thing for me.

Thanks in advance!

You are having Misfires, that is what the flashing CEL is. New coils time. I recommend BHR ignition kit, it uses GM yukon coils. Do not push your car hard with failing coils or you could do real damage. I have yet to pull a misfire in a year of running the BHR kit.


The factory coils are typically known to fail around 30k and it is a common issue.

It almost sounds like a fuel related issue. Considering it was consistent on only one part of the track and he says it has been fine since.

Yeah random misfire but a misfire it is. That is what a flashing CEL is.

I understand that it indicates a misfire. But it seems he's saying it was on the exact same part of the track. At 3/4 of a tank, I couldn't imagine fuel sloshing around and starving the pump...

I say coils going dead

hmmmm, thanks for the help, guys!

Wouldn't the car misfire more regularly if the coils were bad though?

No, those piece of crap just get weak and do weird stuff from time to time. If your car has more than 30K miles on it, just change them. I noticed a slightly smoother pull by swapping them with 35K.

Go Racing Beat Spring and Tokico shocks
Porterfield cermaic brakes

Any reason in particular for the rb/tokico combo? I thought I remember seeing somewhere that the mazdaspeed rear springs were quite a bit stiffer, and I prefer a little oversteer to the alternative so I figured I'd go that way. I'm definitely open to opinions though...

The RB springs and tokico have been tested throughly to match.

wow,

never heard of fuel starving in a left hand turn. :lol:

how much history do you lhave on the car? the issue is the fuel pump..

i do have a bit of knowledge on this.. send me a pm with info..

it can happen at 1/4 tank or 3/4 tank. depends on the pump..



beers :beer:

good job!

beers :beer:

fail..

fix the problem not the blame..

beers :beer:

Could be coils as mentioned above or a set of fouled plugs. It may also be the eccentric shaft postion sensor. A bad sensor will also cause the cel indicator to flash or blink.

Swoope is right......please listen to him!

Long left hand turn, car runs fine otherwise.

AND.......don't you think you might get a flashing CEL(USUALLY indicating misfire) when you fuel starve out??????

When my car fuel starve, it didn't do it. Mine was only a slight hesitation and it kicked back on.

i had the same issue this weekend @ NJMP. the CEL would flash 3-4 times, then go off...i didn't notice any difference in the car when it did that. after it happened once during the third session of the day, i dialed it back and left the car in 4th; no additional CEL flashing. it happened again in the next session when i was pushing the car. we hooked up a reader to the car at the end of the day and there were no codes stored in the ECU.

however, i did also get the stumble several times in the last session; it happened on the front straight. the first time was @ ~7500rpm, then the next lap it started happening at lower rpm (~6000)...i brought it in after that.

it hasn't returned since then. this set of coils/wires/plugs has ~12,000 miles on it. i thought it might be the cat, but that had been replaced under warranty ~10,000 miles ago. i was way low on gas, but this happened on the straight; no trouble in the corners. this morning the car ran to redline with no issue. maybe the fuel pump sock is dirty (~44k on the car)?

FWIW, i've fuel-starved a few times during autoX runs, and have not gotten a CEL.

On the mods issue. I am by no means an expert but I did my research and spoke to people who know more:

RB springs are soft so if you are looking for the track go with a stiffer spring. I went with PT springs & Koni yellows. Currently have the rb sways but going to PT sways as they are adjustable (would benefit me right now - going to Mid Ohio April 1-3rd with some rain expected). If you are going coilovers - best option seems to be KW3s. Finally, stock rotors are good no need to change unless you have a need to spend some cash.

Progress tech website: http://www.progressauto.com/

For pads, I like carbotech xp10 / xp8 or xps all around. Many other good options to choose from.


Cheers.