Subaru Quad AVCS(VVT) is hunching

[andpdas]

I have 2012 JDM Subar WRX STI Spec.C (Ver 11 I guess...)
Engine : EJ207 quad AVCS

I have setup all the VVT stuffs.
Including Camshaft position sensor's offset using the cam angle test.

I took a log and it describes that, intake cams are correctly at the target position.
But Exaust cam pos is hunching(going up and down around the target cam position)

I have both tried cam control mode as SUBARU Quad AVCS and SUBARU AVCS EJ20.
Both of them had the same result.

I have my Link Fury as Piggybacked to my OEM ECU.

But I have disconnected all the cam position sensors, cam solenoids etc.. from the OEM ECU.

Does anyone have any guesses?

Log 2018-04-19 1;31;19 am.zip

G4+Fury-initial51.pclr

[cj]

Your cam target looks stable, the inlet is stable, and the solenoid duty cycles line up with when changes are actually ocurring. So, it looks like mechanically things are behaving and you have enough oil pressure to control the cams. There are one or 2 points in the log where it does eventually settle down too. Its looks like PID overshoot. Maybe the exhaust solenoids in your car are slightly different than those used to generate the default settings.

As per the big warning when you do this, be careful, make small changes at a time, and if things are getting worse, stop quickly and put it back. It looks like you'll need to change the PID mode from default to custom, and then change the settings for both the exhaust cams. Moving the "D" number up a few points should make the cam position stabilise quicker. Comparing the number for intake (40) and exhaust (12), id guess moving it by 5 points at a time is probably safe. If you get it up to 40 and it hasnt helped, try dropping the I value by 0.01, retest, and if needed, drop P by 0.5 and see if that gives you the result you want. Be REALLY careful increasing the "I" value as it can lead to pretty much what you're already seeing where the value constantly misses the target - higher I values cause it to try and get to the target angle quicker (ie too high an I value leads to constant overshoot in both direction)

You may want to hold off making changes to this until one of the link guys has had a look to sanity check my suggestion as its not something you want to just play with.

[Adamw]

Yeah I have a similar feeling to CJ that it is probably PID related.  The EJ207 usually works well with the default PID's but your late model version may have some revisions to some of the mechanical system.  I notice that in your log the exhaust cam control improves a little as engine temp increases, so that kind of makes me lean towards PID.  

Possibly not related, but why does the ECT jump from 67-90°C at 7:05?  

 

[andpdas]

11 hours ago, Adamw said:

Yeah I have a similar feeling to CJ that it is probably PID related.  The EJ207 usually works well with the default PID's but your late model version may have some revisions to some of the mechanical system.  I notice that in your log the exhaust cam control improves a little as engine temp increases, so that kind of makes me lean towards PID.  

Possibly not related, but why does the ECT jump from 67-90°C at 7:05?  

 

Hi @cj @Adamw
Thank you for your advice.
I'll try starting with changing PID settings.

BTW, The reason of the engine temp jumps up is I have changed the trigger pull up for coolant temp.
 

[masservice]

Hey guys sorry to revive the thread but im having a similar issue only Im only on the OEM Ecu, I know where I am but I really cant find any other info online. 
engine is a ej20x from japan (im in the states) using a computer from an ej257 
my right hand avcs over  (and under)  shoots the left hand side is working good but left side is not. 

Just now, masservice said:

Hey guys sorry to revive the thread but im having a similar issue only Im only on the OEM Ecu, I know where I am but I really cant find any other info online. 
engine is a ej20x from japan (im in the states) using a computer from an ej257 
my right hand avcs over  (and under)  shoots the left hand side is working good but left side is not.