m1yeh

My logs consistently show crazy knock values (spikes of 100%) after i enter over run fuel cut while decel in gear (kpa below 20) after fuel is cut.

Setting over run fuel cut off knock value logs look normal.

I’m sure it’s not true knock, but this isn’t normal right?


NB2 OE knock sensor
Ms3pnp
progressive fuel off
timing transition off
fuel return off
timing transition return off

m1yeh

I noticed in my log the crazy TPS accel and MAP accel occur when over run fuel cut turns on.
MAP and TPS accel enrich are set to zero. TPS TPSadc MAP are stable.

Overall, several things go bonkers in the logs when over run fuel cut turns on.

m1yeh

Attached tune and log

curly

iTrader: (25)

That's a strange one. Cyl 1 goes to 0, and 2-4 have what looks like 3 distinct trigger patterns.

What happens when you disable over run fuel cut? What happens when you turn off accel enrich completely (I see it's zeroed out, I mean turn it off off)?

If you haven't already, download the latest firmware and load it, see if that fixes anything.

Also, once you do get this working, you'll want individual fuel and ignition cylinder trims activated. Start with them zeroed out, and when you see one cylinder nosier than the others, add .5-1% fuel to that area, see if it helps. If it doesn't, then add negative advance to that cylinder.

m1yeh

Thanks for weighing in. I wish I could rename the title of this thread to "log goes crazy when overrun fuel cut turns on" because lots of things go crazy. The log throws errors, crazy values, and things that are not turned on. I don't trust the knock values being given, real knock isn't supposed to happen in overrun conditions. In addition, several other things in the log display crazy numbers during that time (TPS Accel, MAP Accel, VVT err, Safety Shutdown, CANrx, VSS Launch, SD Warn, DBW fault, MAP sample error, Oil shutdown, no RPM sync).

When i disable overrun fuel cut, everything in the logs are normal. Therefore, I've narrowed it down to this only happens when overrun fuel cut is triggered.

Thanks for recommending Cylinder Trims. I think I'll leave that alone though because I don't trust the OEM knock sensor enough to tune Cylinder Trims with it. Only enough to adjust the knock gains to match each other under baseline.

This is with the latest MS firmware 1.6.0, Tunerstudio 3.2.03, and MLV 4.5.05.
I will try reinstalling all of the firmware/software, and test out turning eae off off and report back.

curly

iTrader: (25)

If this is an OE knock sensor, it's useless already. Put a Bosch sensor in, and you'll get actual 0-5v values. OE knock sensor reads around 0-0.5v, nearly useless values. Not saying that'll solve your over run issues, just an FYI.

m1yeh

Reinstalling firmware/software, eae off off, did not work.

Same behavior in the log when overrun fuel cut activates several things go crazy.
Turn overrun fuel cut off and everything is normal.

Rrrracer

I've seen this before, but don't remember if it got resolved or not. I think it is a bug and that the weirdness being reported is invalid... for example, your AE is showing active during overrun, but no injector pulsewidth is being commanded.

Try turning off the progressive and transition return settings on your overrun and see if it persists, for some reason I seem to recall it being tied to one of these settings.

You might consider posting over at MSExtra.com to see if the devs can add any insight.

m1yeh

Thank you for your input, I did try that.
Looks like my post finally got approved over on MSExtra, I'm also consulting DIYAUTO.

I agree that it feels like everything is operating normally, just the log goes nuts when overrun fuel cut is triggered.

I've tried and checked:
Progressive return settings off
AFR safety system off
EAE off
Checked overrun TPS threshold
TPS adc is stable

I'll post an update if this gets resolved.