Two questions, spark advance value and knock sensor value

[hanzs]

Hi Yani (or someone who can help),
this is graph of spark advance value (blue), rpm (red) and knock sensor value (green, brown).
http://merkur_sound.sweb.cz//test2a.jpg
It shows, when car rapidly accelerate, that spark advance is over 66 deg. I think it is not possible... maybe there should be a negative spark advance?

The second question - knock sensor value, when engine not running, I think all cylinders should be near zero value.
But this is the screenshot of values:
http://merkur_sound.sweb.cz//v2h.JPG

Bugs or my misunderstood?

[Deckchair5]

HI Hanz
This is a Stilo 1.6 yes? Looks like your latency is too high :~)

KNOCK SENSOR
You only have one knock sensor and it's for all four cylinders so it's normal to have odd values when the engine isn't running. The ecu puts a test signal voltage down to the knock sensor when ignition is on so that's probably what the program is detecting. The ecu knows which cylinder should be firing when it's running so it can work out which cylinder it relates to and its knock signal values from there
When your engine is running then the knock sensor values should be very similar (see below)

SPARK ADVANCE
So difficult to tell from the graphs as the figures are too small but have you read the scale correctly? I can't see what it is from your pictures. it's common to have near 30 degrees of advance. Here's my spark advance (blue) v engine rpm (red) and it has minimum 3 degrees going to 30degrees at 2500rpm when stationary and no load

[hanzs]

Hi Deckchair5!,

About knock sensor - I know there is one sensor and time window for each cylinder, it is clear. The more suprised me different values when key is on. But your explanation, that it is caused by test signal from ECU is good, it can be the reason!

About spark advance - Itried better screenshot (I cant read your screenshot too )
And there is value 6540 deg. on axis Y !! (not 65,40 deg.) Am I right??
This screenshot was taken when I drove a car.
http://merkur_sound.sweb.cz//test1.png

Excuse my poor english

[Deckchair5]

As it seems to be a scaling problem, have you tried it on scale of 1 rather than scale 0.5 ?

[hanzs]

I tried another scale, some error message occurs.

I looks like some strange value of spark advance is received when accelerate...?

[Deckchair5]

Yes that is odd. The most ignition advance i'm getting is around 32 degrees whether using multiecuscan or other diagnostic programs

[hanzs]

I did new testing and export data to csv file. And there is several times value of spark advance about 6400 deg.

http://merkur_sound.sweb.cz//aaaa.csv

I would like to upload the file like attachment, but extension csv is not allowed.

And I did find another problem, I have read fault P0136 - O2 sensor, signal low. Stored. Light ON.
But no MIL light on dashboard.

[yani]

I allowed CSV attachments now.

Yani

[Deckchair5]

there is several times value of spark advance about 6400 deg.
That has to be a program fault

And I did find another problem, I have read fault P0136 - O2 sensor, signal low. Stored. Light ON.
But no MIL light on dashboard.
P0137 is signal low
P0136 is O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
That will be your post cat O2 sensor. I'd clear the code and see if it appears again. It may not appear as MIL yet but it is watching it for a reoccurance of the same fault in the same conditions

[hanzs]

p0136.jpg (9.2 KiB) Viewed 7484 times

About two weeks ago I cleared the fault. And yesterday came again. Maybe there was some short flashes of MIL light in that period, but I´m not sure.
But when I read the fault, the MIL light was OFF. Maybe when fault is in mode "Present" then light ON means currently ON. And when is "Stored" means was ON... I dont know...

But on live data O2 sensor is ok. Maybe there is some short disconnection in connector or something...