Low RPM medium load knock...?

[Robbks]

what's the fuel corrections doing
they were at what, -10 the other day.

got an exhaust leak that's fooling the o2 into thinking it's rich and pulling a heap of fuel, but it actually runs lean and pings?
I guess matt can see it on the logs

[cynner]

It was learned ignition timing that was pulling -11, however I'm not sure if it was due to knock or something else (wasn't able to log at the time). I suspect it was just mildly knocking every now and then for quite a while (6th gear highway, just under boost) until it freaked the ECU out and put it into some kind of protection mode (maybe IAM)...

Have done some logging and it doesn't seem as bad as -11 though... knock is more like -1.4. Will post some logs tonight...

[dr20t]

Check for vacuum / boost leaks

Check fuel pressure regulator and fuel lines are all tight and not losing pressure

02 sensor could be stuffed too - might be giving false reading and therefore actually leaning out then pinging as it transitions from closed to open loop

[cynner]

Here's a few knock events from BtSsm from this evening...

KNOCK DETECTED at 2015-03-17 06:23:44 pm
AFR: 14.4
Boost (psi): -1.4
Boost Target (psi): -2.5
Closed loop: 1
Coolant (degC): 86
FKC (deg): -5.6
FLKC (deg): 0.0
Fuel correct (%): 8.0
Fuel learn (%): -0.2
Fuel pump DC (%): 80.0
IAM: 1.000
Injector DC (%): 9.5
Injector PW (ms): 5.9
Intake (degC): 20
Knocks: 33
Load (g/rev): 0.90
MAF (g/s): 29
Misfire cyl 1: 0
Misfire cyl 2: 0
Misfire cyl 3: 0
Misfire cyl 4: 0
RPM: 1939
Speed (kmh): 54.0
Throttle plate (%): 19.6
Timing (deg): 16.5
Turbo WGDC (%): 3.1
*Learned Timing: 5.5
*Fuel Temp (c): 0
*Exhaust Temp: 342

KNOCK DETECTED at 2015-03-17 06:23:44 pm
AFR: 14.8
Boost (psi): -1.6
Boost Target (psi): -2.6
Closed loop: 1
Coolant (degC): 86
FKC (deg): -2.8
FLKC (deg): 0.0
Fuel correct (%): 6.0
Fuel learn (%): -0.7
Fuel pump DC (%): 80.0
IAM: 1.000
Injector DC (%): 8.9
Injector PW (ms): 5.6
Intake (degC): 20
Knocks: 32
Load (g/rev): 0.91
MAF (g/s): 29
Misfire cyl 1: 0
Misfire cyl 2: 0
Misfire cyl 3: 0
Misfire cyl 4: 0
RPM: 1908
Speed (kmh): 53.0
Throttle plate (%): 19.6
Timing (deg): 18.0
Turbo WGDC (%): 5.1
*Learned Timing: 5.5
*Fuel Temp (c): 0
*Exhaust Temp: 342

KNOCK DETECTED at 2015-03-17 06:23:44 pm
AFR: 14.2
Boost (psi): -2.0
Boost Target (psi): -3.6
Closed loop: 1
Coolant (degC): 86
FKC (deg): -2.8
FLKC (deg): 0.0
Fuel correct (%): 3.1
Fuel learn (%): -1.2
Fuel pump DC (%): 80.0
IAM: 1.000
Injector DC (%): 7.9
Injector PW (ms): 5.1
Intake (degC): 20
Knocks: 31
Load (g/rev): 0.87
MAF (g/s): 27
Misfire cyl 1: 0
Misfire cyl 2: 0
Misfire cyl 3: 0
Misfire cyl 4: 0
RPM: 1870
Speed (kmh): 52.0
Throttle plate (%): 18.8
Timing (deg): 21.0
Turbo WGDC (%): 3.1
*Learned Timing: 5.5
*Fuel Temp (c): 0
*Exhaust Temp: 342

[cynner]

And a log file... https://dl.dropboxusercontent.com/u/717 ... _knock.csv

If anyone is bored and feels like having a glance at the logs, feel free

The knock seems fairly constant as to when it appears.

Is this kind of low load/low RPM knock potentially fatal to the engine? (am I playing with fire by driving it like this?)

[dr20t]

Is it after you dab the throttle or even when throttle is constant ?

8% correction tells me fuel table is out indicating boost / vacuum leak or 02 sensor playing up. However if happening when you dab the throttle it could be tip in enrichment not being right and either rich or lean mixture causing knock on throttle application.

Still check the things I mentioned earlier (also realized robbks also gave similar advice which I hadn't seen before)

[Robbks]

right as you roll onto the throttle, the WGDC moved from 0%, up to 5% and back off.
it pulls 2.8deg then up to 5.6deg while it's Adding in up to 8% fuel.

so it's running lean and knocking on tip-in

check out all those intake pipes and vac lines.
can of UEC around the joins, etc, all over the intercooler (check for a pinhole)

Here's my strip out of the data
you see you roll on the loud pedal, AFR dips as it should but look at fuel correction trying to maintain that AFR,
turbo comes on boost, AFR goes slightly lean again and it knocks

Kim Knock.JPG (101.25 KiB) Viewed 2903 times

[cynner]

Thanks guys, I'll try the UEC to look for leaks.

Could the Wastegate actuator be jamming or stuck or something? (would that cause issues?). Or something internal within the turbo?

(as this is a relatively new turbo... had it for around 6 weeks before this issue surfaced)

Kim

[dr20t]

Its definitely fueling or boost/vacuum leak related

This is made clear with the fuel trim corrections coinciding with the knock

[cynner]

Two things fixed... 1) turbo inlet hose was slipping off. Fixed.
2) up pipe gasket was leaking. Fixed.

Problem is still there

The whole manifold has been removed and re-assembled. Problem still there.

No one can figure it out Here's the latest log files - https://www.dropbox.com/s/ftvy3hbogshdr ... k.csv?dl=0

It pulled -11 at line 4600-ish...

Frustrating

[dr20t]

What's your timing and avcs table look like?

[cynner]

Edit. Tune screenshots removed at tuners request.

[dr20t]

Who did the tune? You need to speak to them about it.

[KiDo_Tuning]

Who did the tune? You need to speak to them about it.

Already have. Pulling timing results in preignition, more timing still has same amount of timing being pulled.

Ran perfectly until the exhaust leak started

[dr20t]

Didnt realize it was your tune. Perhaps he should pull your timing and avcs tables down.

For the record your cruise base timing is alot lower than non cruise, although without seeing kca I don't know what total looks like.

Cynner have you checked your maf sensor?