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Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Tue May 27, 2014 1:20 pm
by bigBADbenny
Yes its probably OK.
The not OK is is huge differences, lots of lag, and oscillation between L & R values at certain RPM's and dricing conditions eg cruise, idle.

The system is self calibrated, so assuming no other faults or CELs, reset the ecu and watch the recalibration process happen after the 2nd key on, or log it.

I noticed more lag after I went to heavier oil so I reset the ecu for good measure ;)

I'll swap the OCV's side to side next service so they age or clog or? at the same rate..

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Tue May 27, 2014 1:29 pm
by KiDo_Tuning
klam wrote:is the slight out-of-sync value between two intake valves ok when accelerating ? I'm talking about +/- 10 degrees... once the car reaches above 2000+ rpm or not accelerating heavily, the difference between them is around +/-3 degrees which I reckon is ok.


Fine :)

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Tue May 27, 2014 9:36 pm
by klam
-thanks.

I still had a slight shake here and there, but this time it wasn't as strong as previously, so I've decided to change the spark plugs, and found that one of the spark plug's ceramic coating was shattered... new wider gaps plugs had resolved it, though now the car is slightly more sluggish due to the gap. waiting for a new map now though..

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Sat Sep 13, 2014 9:46 pm
by BlackSTI
Stationary:
Image

4th Gear:
Image

5th Gear:
Image

6th Gear:
Image

Lag:
Image

Other interesting:
Image

I am still digesting if the lag and +/- 1 degree is an issue and what the fix would be.

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Sat Sep 13, 2014 9:56 pm
by bigBADbenny
The sawtooths in those logs are +/- 1 degree, so I don't think they represent an issue.
Same for the lag, which soon catches up with the target.

Image

This is from page 6 of this thread, the oscillation and lag (blue line) were measurable in 10's of degrees of deviation from the fully functional OCV (green line) :)

X axis is time vs Y which is VVT angle(0-50 degrees).

Oscillation is evident at X: 250 to 750 and lag at X 800
The lower graph is RPM vs time, looks like 3rd, 4th 5th 6th freeway then some traffic.

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Tue Sep 16, 2014 3:53 pm
by BlackSTI
bigBADbenny wrote:The sawtooths in those logs are +/- 1 degree, so I don't think they represent an issue.
Same for the lag, which soon catches up with the target.


Thanks for your help once again Benny!

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Tue Nov 18, 2014 11:27 am
by FOZxtc
this might just be my Get Out of Jail Free Card with my fresh engine build with cosworth S2 grind 278 cams...

I have also copied this info to ozfoz

thanks!

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Tue Nov 18, 2014 11:33 am
by bigBADbenny
Nice one - post a link plz :)
Ps I have vvt gauges using btSsm on my factory Nav screen.
Nice to have real time display for peace of mind.
Exhaust vvt has been added for dual avcs engine :good:
Lmk if you want to test it on your car...
Image

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Wed Feb 25, 2015 6:50 pm
by Tanetoa
Is there a walk through for replacing this part, or is it best left to the professionals?

I'm also guessing its better to get this fixed before adding a 3 port boost solenoid and a tune. But is it mandatory?

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Wed Feb 25, 2015 7:07 pm
by bigBADbenny
I made photos last time I did it. I'll dig them up :)
Since you're in Melbourne I can do the install with you, or solo.
It takes about 90 minutes to do both sides or less if you know which ocv is failing.
I have about 4 spare ocv's or order new from eg Celtic, Underdog, Flatirons, RSD, eBay or Makin & Luby.

I strongly recommend fixing the issue before tuning as the issue affects your idle, cruise and afaik it can't really be tuned around, meaning you won't get an optimum result.

But the install is quite easy, and the parts are relatively inexpensive.
Plus we can log your car so the tuner can be confident it's healthy.

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Wed Feb 25, 2015 10:55 pm
by Tanetoa
Thanks again Benny. Really appreciate both offers and your help.

Thanks to Matt, I have the part already. The CEL code is P0021, which I'm told means it's the passenger side and afaik this part should solve the issue. Atm I'm unable to use S# without it throwing the above CEL code.

I'm free this Friday and Saturday or we can sort it via PM.

Cheers

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Thu Feb 26, 2015 12:09 am
by bigBADbenny
Passenger side is easiest :good:

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Tue Mar 10, 2015 7:08 pm
by KiDo_Tuning
Fixed? ;) hahaha

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Tue Mar 10, 2015 7:35 pm
by bigBADbenny
Apparently it's all fixed for now :)
Jayson got the OCV's express posted from partsouq for around $130 delivered. :)
viewtopic.php?f=55&t=29471

Re: AVCS VVT angle out of sync diagnosis MY07 GT B

PostPosted: Mon May 11, 2015 5:03 pm
by twisties
Hi all,

I've come across this thread while trying to fix a hesitation/stutter issue on my 09 XT Foz. I also got the CEL code P0011 which is drivers side OCV solenoid.

I removed the avcs banjo bolts on the weekend and found the filters had already been removed. I also tested both OCV's with a 9v battery and they both moved freely. Reassembled the car and the hesitation still exists. Is it possible that the OCV's can still be failing even though they respond normally when tested with the 9v battery?

I don't have a tactrix so I've been unable to log any of these parameters (although I do have torque and an ELM dongle, though they don't seem to be capable of measuring VVT - unless someone knows how to make a PID in torque to measure that?)

I don't really know what else to try now so I'm thinking of just replacing the OCV's anyway.. (can get 2 OEM delivered from partsouq for about $160aud).

Does anyone have any better ideas than that? Any help is greatly appreciated :)