btw it looks like the line with less VAC goes to the Jet Air Fuel Mixing Nozzle

WAG.. Even though you still have the screens in place, is it possible there is excessive turbulence right before the MAF bulb inside the CAI? Which in turn is causing the MAF to send inaccurate reading to PCM.?

Do you still have the stock air box?

In a few cases I have seen low coolant levels cause the engine coolant sensor output to
fluctuate, and put system in open loop.(quick check- unplug coolant sensor.

nope, aem. It was doing this with the oem as well so I can rule that out.

k, after unplugging it what should I do. Out of curiosity I did unplug it earlier today, and plugged it back in to make sure it was seated properly.

I refilled fuel today, didn't put any premix in though. I am wondering if maybe I am starving the engine by using too much premix. I have been using 6oz premix, 1oz FP Plus. I figure it will take a bit for the newer ratio of fuel to premix to start being fed into the engine.

The 'too much pre-mix' did cross my mind...as a 'maybe'.

It pays to fill with gas ONLY every 5 or 6 fills to dilute the pre-mix in gas left behind when you do normal refills/add premix....much depends on how low gas gets when you re-fill and your premix add calculations.

Coolant Sensor, has NO correlation whatsoever to your issue, it is a 'level' warning light, that is all, unplugged, plugged in, or 'a' defective sensor has no effect on the engine management.

Yea I mean I know a lot of the S1 guys use a significant amount of premix on their cars (upwards of 8oz on some daily drivers), but maybe us S2 owners dont need as much since we have that 3rd oil injector. Over here the highest octane we have is 93, so maybe I am just killing off the octane levels with the amount of premix I am putting in. It will be interesting to see how the next week goes.

ASH8, Coolant Temp Sensor,B59318840A, not talking about level sensor.

ASH, any significant differences between removign the UIM of a S1 and S2? I took pics along the way when i removed my UIM during diagnosis, didn't know if it was worthy of a DIY.


Oh i misinterpreted as well. I haven't tried this.

OK..Yes..these don't give issues normally, and if it was defective both dash temp and red LED RPM temps would not work correctly.

No real difference, except TB one (intake) has one less/different breather hose for the S2 specific black Oil Filler chamber unit.

And some of the 'vac'/breather lines are different plus the EMOP Oil return pipe clicks into this oil chamber neck.

sounds like its misfiring while just idling to me....or maybe im hearing things. Have you checked to make sure the screens are seated correctly in the intake tube?

edit: i read above, apparently you have checked.

My car will also burble at idle depending on what mood it's in. I use 8 oz/13 gallons without difficulty; 8/1664 = 0.46% which is way far from being enough to lean the a/f. Many premix oil, rather few add fuel cleaner at every fillup, though.

Fuel starvation remains a possibility. Fuel pump of course, but also clogging of the sock over the gas pickup and possibly clogging or malfunction of the P2 or S1 injectors.

It remains an odd coincidence that the stumble happens right when the VFAD should open. Did you cap the vacuum port on the UIM or down somewhere past the VFAD actuator?

I did, I have a cap on the nipple on the throttle body. But remember that this used to happen before any modifications to the stock intake system.

It would be interesting if it is indeed the fuel pump. I dont know for certain, but I have yet to hear of an S2 pump failing. From what I can remember, the S2 pump is far superior to the S1 pump. That doesn't mean that it cannot fail, but I would think unlikely at 10k miles. Not to mention I never run my fuel far into the red. Only a few times have I seen my low fuel light on.

My flutter has been solved, like I said, My coolant sensor plug was unplugged my the dealer to mask a faulty coolant reservoir and "coolant carrosel light" Plugged it back , reset kam,nvram and drove 3 days and problem solved. It remapped my complete computer into thinking it was overheating so it put the car in walk mode.

OK.......?? (your ECU reset possibly fixed your issue, not what you said before that..)

Can we at least get the interpretation correct...:)

The Coolant LEVEL Sensor inside the Coolant Bottle has NO, repeat NO, control over engine management..none..

It is only for the dash 'radiator' idiot light...you can unplug it, no light, no issues, except you wont get any warning light if and when coolant in bottle is low, and or engine or radiator.

This Coolant Level Sensor in the Coolant Bottle is the ONLY sensor which warns of low engine coolant from the Coolant Bottle...NO 'CEL' or DTC reported.

.......................................

Now..what others call Coolant Sensors for Engine/Coolant temperature is a different issue and beast, and not easily disconnected/renewed...

I prefer to call them "Temperature Sender Units", because that is what they are and do.

IF this becomes defective (which can happen) or is disconnected, then yes, issues will occur, like no working temp gauge on dash, no 2 red RPM LED off (S2's), ECU (PCM) unable to monitor engine/coolant temps, CEL light will result and possibly LIMP mode and or performance issues.

These Temperature Sender Units (B593-18-840A) are very reliable and have been in use since 1991 on a multitude of Mazda models from Mazda 626,323,Protege, CX-7, Mazda 2,3, B and T series trucks, Miata's..RX-8...and well before current OBD management DTC protocols.

Ok well my flutter has been resolved.

Turns out the issue here was that for some reason my spark plug wires not only got dirt inside of them, but didn't have a solid connection to my coil packs. So I fixed up the wires, cleaned them out, reconnected, and made sure idle was good.

Once that was set, I followed TeamRX8's spark testing instructions to verify all coils were firing properly. Once I confirmed each coilpack, I took her for a drive .... flutter gone.


My name is paimon, and I am a newb.

Geesh. Well, you learned something at least.

Paimon, what did you actually use to clean your spark plug wires

In case you aren't aware, spark plug wires usually have boots that can be slid back on the wire -- and are supposed to be slid back -- so the end of the wire can be confirmed to firmly clip onto the electrical terminal. Only then should the boot be slid forward to cover the connection.

Lots of people just jam the spark plug wires into place and if they don't pop off, they "must" be seated properly.

MAF sensor cleaner. Safest bet when cleaning spark plug wires.

LOL!

I told you it was ignition misfire!

Revive this thread.

So the flutter has came back! it went away for a while and now it is back, WTF is all i can say I use 93 octane , i have a turboxs exhaust with racepipe and aem intake, i have a popping at idle(thought it was missfirin) but the fllutter is back :( coils and wires all work , plugs all seem to be in good shape!

Have a look at the latest M-Tip I posted, idle dip or wandering due to intake screens and panels removed, according to MNAO.

I am just wondering 'IF' you could re-install your OE Intake, box and filter?, what will happen?

But your (flutter) is at high RPM..correct?

Either ignition or SSV.,,can you or do you run pre-mix, try that for a while and see "if' it might free up sticking SSV?

D585 coils and the OE dwell table do not a good combination make above 5000 rpm

sucks for us S2 guys :mad: I think this might be my main issue here, since my fluttering is back, only this time it looks like it is closer to 9k. I can easily pull to 9.5k (viewed on tach, not actual) though unlike before which maybe was caused by my poor wiring skills.