Hello All,
I have an odd sputter that I am trying to chase down-
When I floor the gas pedal (WOT) my rpms will sputter around 6 or 7k and not go above 7k.
However, when I am not flooring it I can go all the way through redline.

I'm almost leaning toward an injector (secondary) issue, since it will redline fine when not driving hard. Does this make sense? There's also NO issue with hot starting or anything else. It idles flawlessly as well.
I was also wondering if maybe it was the SSV not opening at the drop of a hat? It will ease open, but won't burst open.

I'm hoping one of the veterans here will have some insight on if I am going the right direction or not.

Thank you all in advance,
-Jon

 

I should add that this did result in two separate misfires, throwing the P0302 code.

 

You should post the Freeze Frame data from your ODBII reader, that information can provide some more insight to issues
(for example LTFT and STFT etc)

When was the last time you changed the spark plugs or the coils?
Have you tried the inspecting the spark plugs?

It would also be worth your time while you're inspecting the plugs to check and/or clean:
- ESS
- Maf
- Air filter

There's several great threads on this site to help you diagnose misfires.
I wouldn't be suspecting the SSV at this point, or the injectors.
Check the simple stuff first, especially as you've got a misfire code.

 

I agree, I'd look at plugs/coils/wires.

 

Thank you for your reply!

The coils and wires are BHR so I don't think it is them, but I will put a timer on them and see.
Spark plugs are on my list and I'll check them tonight.
Wouldn't the other things happen at higher RPM even without the WOT? I figured WOT would be causing an air/fuel delivery issue, since it only happens then and not any other time.

I'll check it all anyway and post back when I have something.

 

I'll look, thank you!

 

Ok even the best coil in the world can fail, but specifically check that the ground wire to the BHR coils is in good condition and the grounding point is fastened tightly and no corrosion.

The other things may not occur without being under wide open throttle because the engine is not demanding that much fuel.
When the engine is under high load, high rpm, there is a lot of air flowing across the Maf and the ECU is going to be commanding a lot of fuel.
Almost always if you are experiencing misfires especially in the high load and high rpm's it's do to weak ignition.

It's not the same as revving the snot out of it parked in your driveway.

 

Makes sense. I did have a BHR coil fail on my 04, so I know it can happen.
Thanks again for the knowledge! I'll post back my findings this evening.

 

Also recently had an unknown age BHR coil fail. Replaced and car is back to normal.

 

they fail as often as OE coils imo, but let the lemmings have their lore … :shocker:

 

You've been tracking for a while, right? What coils do you run?

 

Upon direction from Charles I ran an induction timing light on each spark plug wire while the car was running. On a cold engine my L2 rear leading coil had an inconsistent strobe but once fully warmed up it seemed fine.
Swapped all the coils out with oem and did the 20 brake stomp reset and now there is no sputter anywhere through the power band.

Here is a video of what I was experiencing when taking off from a cold start. It would do this above 7k-9k off and on at random until it became a constant misfire on my rear rotor.

Rumor has it that team runs a custom ign aem coil setup :P

 

UPDATE/SOLVED
Sorry for the delay- as I was pulling out the air box and battery I got annoyed at how crammed the engine bay was with such a small engine so I relocated the battery (trunk) and fabricated my own intake (based on the AEM/MazdaSpeed).

To recap- I was having an issue with a sputter above 7k RPM. This only happened when I floored it, not if I 'lazily' accelerated. I wasn't getting an error at first; I had to ride it pretty hard in order to finally get a rotor 2 misfire.
For troubleshooting- I started with the ignition system as recommended. I swapped the Rotor 2 coils with the Rotor 1 coils, keeping everything else the same.
After swapping the coils, moving the battery and installing my fabri-cobbled intake I had the same sputter. I again 'rode it hard' to get another error, this one was now a misfire on Rotor 1 (which is what I was hoping for). I then swapped an extra coil in place of one of the ones presently mounted on Rotor 1- the idea here was that if the sputter still existed, it was almost certainly an issue with the other coil on that rotor.
Swapping in the extra coil solved the issue.

I hope this helps anybody else having a similar issue!

 

Thanks for the updates!
Updates are always appreciated.
Glad you figured it out

 

Of course! I hate finding posts explaining the same issue I have but no resolution haha.

Plus it's almost impossible to find threads in the first place.

 

Installing Sakebom's remotely mounted 1GN-1A coil pack & harness solved all my ignition issues.

 

Solved yet?