[Sluty6]

QUOTE (jm6s @ Mar 31 2009, 11:16 PM) index.php?act=findpost&pid=1541070

Excellent idea on swapping the injectors. I'm going to try that and if the misfire jumps to a different cylinder then I know for sure it is the injector. I'm familiar with GM injectors which are easy to remove from the fuel rail, just a metal clip and an o-ring. I'll have to take a look at the ones on the mazda and see how they are secured.

I have a friend who is going through a very similar situation with an 04 RX8.[/b]

Have you checked the Crank position sensor? did you install the new Fluid dampr crank pulley?

I had a misfire problem for months till I finally cranked down on the crank pulley... only moved a fraction of an inch but have been misfire free ever since.
I do have the Fluid Dampr... but you never know maybe the stock one loosened a bit.
I had the same symptoms... cruising speed misfire CEL! Also check into the the crank sensor and i think the cam position sensor can cause misfires as weel

 

[jm6s]

QUOTE (rkeytek @ Apr 1 2009, 06:58 AM) index.php?act=findpost&pid=1541175

Have you checked the Crank position sensor? did you install the new Fluid dampr crank pulley?

I had a misfire problem for months till I finally cranked down on the crank pulley... only moved a fraction of an inch but have been misfire free ever since.
I do have the Fluid Dampr... but you never know maybe the stock one loosened a bit.
I had the same symptoms... cruising speed misfire CEL! Also check into the the crank sensor and i think the cam position sensor can cause misfires as weel[/b]

The pulley is original and has never been touched so I imagine that can't be to blame considering how tight those things are on there. If someone has the torque spec I can check it just to be sure. At this point I am really hoping it is the fuel injector as that would be a quick/easy and more importantly cheap fix! I feel like I won't be that lucky though.

 

[hot6onaplatter]

make sure the intake manifold gasket is in place and not messed up

 

[showhat9]

QUOTE (jm6s @ Mar 31 2009, 05:33 PM) index.php?act=findpost&pid=1540897

Update:

Finally had some time to look back into this. I replaced all 6 coils with BRAND NEW Motorcraft coils. I took a look at the plugs while I had the intake manifold off. They look really good - perfect even.

So 6 new coils, perfect plugs with less than 2k on them and sure enough come 85 mph check engine light comes on, push it past 85 and it'll flash indicating a serious misfire. Still P0301.

I am so frustrated at this seemingly unsolvable problem. I've established that its not the plugs, not the coils and the wiring on the coils looks perfect. Only thing left is a bad injector on #1 or a faulty ecm. What is so strange is that it seems to have nothing to do with engine RPM but rather road speed. Though, if I am accelerating hard though I can whiz right past 85 and no CEL. Ease up or coast and it'll pop right on.

What can this be if not coils/plugs? It runs perfect throughout the whole ordeal - if not for the CEL I would never suspect there to be anything wrong. I'd hate to replace the injector and still have the light come on. I don't want to throw more parts at it in hopes of resolving the issue. Has anyone had this happen??[/b]

COP's are fairly predictable. Like a light switch - either it works or it don't. Before you go nuckin futz I'd swap 1 to 2 and vice versa. If you still throw a code, I would suspect the loom. Just a hunch from way to many years of chasing gremlins on COP cars. I know this sound nutz - grab the loom and give it a good yank and see what happens. Yes it's a stretch but trust me BTDT w/ freakin coils.

 

[jm6s]

I swapped each fuel injectors to a different location. I checked all the wiring/loom on the injectors and coils - all appears ok.

So with each injector in a different spot.... still the same damn code! P0301, misfire on #1. So at this point I've replaced just about everything it could be including coils/plugs/injectors. And yes the manifold gaskets appear ok and are seated correctly.

I'm out of ideas. I don't want to bring it to a dealer because they are going to go down the same path as me and tell me first I have a bad coil pack, charge a fortune to replace it, realize it isn't the problem and then continue to throw parts at it all the while running up the bill and claiming each of these parts was bad. Any other ideas? It really doesn't appear to be a wiring issue. Can the computer itself be bad? I'd hate to keep throwing parts at it but I really don't know what to do. Can I get the computer reflashes? Would any dealer do this, and how much could I expect to be charged? Keep in mind the engine runs perfect through all of this.

 

[hot6onaplatter]

if the car runs fine i wouldn't worry about it. if it starts shaking or having loss of power i would, but honestly is it worth it throwing time and money at a such a mysterious problem? not if the car drives fine in my mind.

I'd just be curious to know what the the hell it is! ECU is my best guess but geez thats a toughie

 

[jm6s]

QUOTE (hot6onaplatter @ Apr 11 2009, 10:49 AM) index.php?act=findpost&pid=1546111

if the car runs fine i wouldn't worry about it. if it starts shaking or having loss of power i would, but honestly is it worth it throwing time and money at a such a mysterious problem? not if the car drives fine in my mind.

I'd just be curious to know what the the hell it is! ECU is my best guess but geez thats a toughie[/b]

I have a friend with an RX8 that has the same problem, after spending hundreds he came to the same conclusion as you did. I can't let it go. For one if there is something wrong I want to fix it, and the other part is I can't stand seeing that service light on!

 

[hot6onaplatter]

haha i know that bug. must fix!!! i got the same problem with the heater circuit on my 02 sensors, well at least i can clear mine on startup and they stay off. its been like a year and i have a few theories, but the car runs fine... soo... yeah, haven't messed with it. i don't know man, its hard to give it up. luckily for me its harder spending money on it. who knows one day you may stumble on the answer.

Also an acquaintance i know had a similar problem with an ever occuring CEL. this person owns a successful hedgefund, so they have a bit of spare dough *cough* *billions*. so she got a japanese engineer that worked on designing the car to replace the entire wiring harness and rewire the whole thing. STILL threw the cel. she of coursed hired a team of lawyers and got all her money back, but you get the point. sometimes these bugs are so deep that it would require an ECU change to fix it.... and if its running fine it aint worth it!

 

[jaysonday]

jm6s, I am also having the same CEL code P0102 and I also get it going at higher speeds roughly 80 to 85. Any luck on this?

 

[0MGHAX]

I was getting this lovely P301.

it was actually a vaccum leak (the hose burned and snapped)

so I'd check for vaccum leaks if I were you.

I changed the plugs and the one coil that was "bad"..it stopped throwing a code for a little bit but then it happened again.

 

[jm6s]

The only luck I've had is keeping it below 80.

I didn't notice any bad vacuum lines but I didn't really go hunting for them either.

OMGHAX, might I ask where your bad vac line was?

 

[0MGHAX]

if you're facing your car its a hose plugged in to the right of your Intake Manifold.

I ghetto rigged this picture but u get the Idea, it runs below the TB and it was snapped dead in the middle.

 

[jm6s]

QUOTE (0MGHAX @ May 13 2009, 09:11 AM) index.php?act=findpost&pid=1560111

if you're facing your car its a hose plugged in to the right of your Intake Manifold.

I ghetto rigged this picture but u get the Idea, it runs below the TB and it was snapped dead in the middle.[/b]

OMGHAX... I need to thank you, I believe you led me to the cause of my problem. I thought long and hard about any vacuum lines I may have touched recently, then it occurred to me that this problem arose soon after installing my HIDs. And to install them I had to remove the airbox, which has a vacuum line for the flapper. Sure enough, I popped the hood and the flapper vac line was not plugged in. I haven't taken it for a spin at that kind of speed since reinstalling it but I'm willing to bet that must have been the problem.

Looking back through this thread I see that ShockFX suggested a vacuum issue way back in February! Wish I had given it more consideration back then.

 

[0MGHAX]

QUOTE (jm6s @ May 15 2009, 04:16 PM) index.php?act=findpost&pid=1561270

OMGHAX... I need to thank you, I believe you led me to the cause of my problem. I thought long and hard about any vacuum lines I may have touched recently, then it occurred to me that this problem arose soon after installing my HIDs. And to install them I had to remove the airbox, which has a vacuum line for the flapper. Sure enough, I popped the hood and the flapper vac line was not plugged in. I haven't taken it for a spin at that kind of speed since reinstalling it but I'm willing to bet that must have been the problem.

Looking back through this thread I see that ShockFX suggested a vacuum issue way back in February! Wish I had given it more consideration back then.[/b]

Sweet, always glad to help anyone! hope that was it and enjoy the zoom zoom

 

[jm6s]

QUOTE (0MGHAX @ May 16 2009, 08:30 PM) index.php?act=findpost&pid=1561470

Sweet, always glad to help anyone! hope that was it and enjoy the zoom zoom[/b]

CEL came back under same conditions =(

 

[0MGHAX]

QUOTE (jm6s @ May 17 2009, 02:03 PM) index.php?act=findpost&pid=1561632

CEL came back under same conditions =([/b]

damn! I switched from NGK's back to stock when i changed my Plugs and the 1 coil (I bought a brand new coil)

 

[jm6s]

QUOTE (0MGHAX @ May 20 2009, 11:07 AM) index.php?act=findpost&pid=1562705

damn! I switched from NGK's back to stock when i changed my Plugs and the 1 coil (I bought a brand new coil)[/b]

I have 6 new coils and plugs, swapped fuel injectors and found/corrected a vacuum leak. My last guess now is ECM but I don't want to throw more money at it in a guessing game.

 

[0MGHAX]

QUOTE (jm6s @ May 20 2009, 12:18 PM) index.php?act=findpost&pid=1562757

I have 6 new coils and plugs, swapped fuel injectors and found/corrected a vacuum leak. My last guess now is ECM but I don't want to throw more money at it in a guessing game.[/b]

oh man, with all of that I would've taken it to the dealer by now without replacing all the (maybe its this) parts.

 

[jm6s]

QUOTE (0MGHAX @ May 21 2009, 07:14 AM) index.php?act=findpost&pid=1563055

oh man, with all of that I would've taken it to the dealer by now without replacing all the (maybe its this) parts.[/b]

Well the only expensive part was the coils. I got 6 brand new OEM coils for $100 on ebay. Plugs it needed regardless as they were original at 80K+. The injectors I didn't replace, rather I switched each injector to a different location in the fuel rail, that way if the injector was at fault the misfiring cylinder would 'move' with the bad injector and throw a code for a different cylinder therefore identify the problem as the injector. I tried this with the coils as well but I replaced them anyway. Regardless of what I did though, 85mph in 5th equated to P0301. I'll hunt around a bit more for vacuum leaks I suppose.

 

[lacuna]

I have also heard of burned valves, and bad cats causing this code. Seems like your either going to have to deal with it, or do a which hunt. To bad you don't live close to another member that has a 6s to swap ecu's with.