Tuna was correct, the AVCS sensors are not compatible with the crank sensor as you have found out. Sorry there. My bad. I should have pulled them instead of eye balling it :(

Its the crank/cam sensors that are the compatible ones. Not the AVCS ones at the back of the heads.

Having had a another think about this.

Rexy, try disconnecting both left and right AVCS solenoid electrical plugs and then going for a drive to see if your problem still appears. The AVCS Solenoids are to the front left and right on top of the heads (in front of intake manifold), same type of plugs as the AVCS cam sensors from memory.

Your AVCS system is likely to throw up a CEL (Check Engine Light) but don't worry as the Cams will just default to running on their grinds. There should be a loss of mid range torque though which will be noticable when driving.

Go for a test drive and see if the jerkiness during WOT disappears.
If it does then you have an AVCS solenoid - Oil pressure issue.
I would then reconnect the plugs and do an oil change to Mobill S 10w-40 Semi Syn and see what occurs.

However if the jerkiness is still there during Wide Open Throttle with the car loaded up in 4/5th gears you have a different problem. It will be dyno time with Engine logging to really see whats going on.

J

Had same AVCS prob on my 03 STI after ECUTEC reflash and tune from Maximum Motorsport took it back to Steve from Maximum and he plugged in Delta Dash and we went for a run and it showed up no advance in the cam timing under hard throttle but all else was ok, so car suffered from loss of midrange.
He was able to fix this prob with the AVCS and has had this prob before with other STI's cost of fix was under $200 but he wouldnt shed any light on what the cause was.
Never suffered from jerky prob just down on power.
Hope this is of some help, if not maybe someone else may ring a bell.
Steve.

[QUOTE=WRXTASY]Try disconnecting both left and right AVCS solenoid electrical plugs and then going for a drive to see if your problem still appears. The AVCS Solenoids are to the front left and right on top of the heads (in front of intake manifold), same type of plugs as the AVCS cam sensors from memory.

Your AVCS system is likely to throw up a CEL (Check Engine Light) but don't worry as the Cams will just default to running on their grinds. There should be a loss of mid range torque though which will be noticable when driving.

Go for a test drive and see if the jerkiness during WOT disappears.
If it does then you have an AVCS solenoid - Oil pressure issue.
I would then reconnect the plugs and do an oil change to Mobill S 10w-40 Semi Syn and see what occurs.

However if the jerkiness is still there during Wide Open Throttle with the car loaded up in 4/5th gears you have a different problem. It will be dyno time with Engine logging to really see whats going on.

J[/QUOTE]
Ran this test and resulted in - check engine light - loss of mid to upper rev range power - much reduced jerky acceleration ............

Changing oil to Mobil synth s 10w/40 anyway and will get ECU reset...

[QUOTE=greenie]Had same AVCS prob on my 03 STI after ECUTEC reflash and tune from Maximum Motorsport took it back to Steve from Maximum and he plugged in Delta Dash and we went for a run and it showed up no advance in the cam timing under hard throttle but all else was ok, so car suffered from loss of midrange.
He was able to fix this prob with the AVCS and has had this prob before with other STI's cost of fix was under $200 but he wouldnt shed any light on what the cause was.
Never suffered from jerky prob just down on power.
Hope this is of some help, if not maybe someone else may ring a bell.
Steve.[/QUOTE]
Thanks Greenie....
There is a few reports of this problem in threads on Rexnet
apparently MRT has a fix for this one
But it is not what I am experencing.................

Oil changed to Mobil synth s 10w/40 and ECU reset
engine runs quieter and a little smoother
this oil is definetly thicker to pour than the valvaline 5w/40 I prevously ran

result = no reduction in jerky acceleration at WOT ...........

Bit of a bugger of a problem, this one.
At least by disconnecting the AVCS solenoids you have identified part of the problem thats causing the jerkiness.

I would not discount the Oil change immediately either and give the AVCS solenoids a week to try and fully activate again and return to normal operation.

If after say 400-500km your still having problems its time to see Steve at Maximum Motorsports for some cam logging, and a possible mechanical fix.

Give it a week and report back. Patience grasshopper.

[QUOTE=WRXTASY]Bit of a bugger of a problem, this one.
Give it a week and report back. Patience grasshopper.[/QUOTE]
OK thanks WRXTASY and everyone else for your help.
Im running this by Subaru Australia but so far they are backing up the dealership in saying it is a characteristic of the vehicle.
Must come with age !

I would get some cam logging done and if they are found not to be working properly, save the data and then present it to Subaru Australia and demand they fix it free of cost.

They know about this problem through MRT and refuse to acknowledge it even exists. If enough owners make enough noise over the issue, Subaru Australia may fix it free of charge to affected owners.

$200 is a small cost for Subaru Oz, considering only a small number of owners are afffected.
I would be making a fuss if it eventually turns out to be the AVCS issue.

Good luck. :)

Similar problems here :-

[url]http://www.wrxfanatics.com/index.php?showtopic=15015[/url]

.

This is a long overdue update on the problems I had with my MY03.
After changing the Engine oil from Valvoline Fully Synth 5W/30 to Mobil synth s 10w/40 as discussed above and getting the ECU reset at Subaru there was no noticeable difference...........

WRXTASY recommended I run the car for a few hundred Ks and see if it improved, and it has.
The car does not always run smooth I get the same jerky acceleration every now and then (mainly when on a long drive and giving it WOT to overtake )
But overall there is a huge difference and I am enjoying my WReX much more.
I feel that acceleration has been slowed a little probably due to the thicker oil retarding the turbo spool time but its a very small sacrifice.

Anyways Im a happy little WReX owner now and thanks to WRXTASY for coming to my aid in the first place and thanks to everyone who had some input into this thread, I hope other newbie`s get some benefit from this post.

Who was the dealer concerned?

Given the number of mechanics who have diagnosed this fault and provided feedback to Subi Aus you would expect them to know what the cause and fix is

Other competent mechanics have diagnosed this fault, saying who was the first is just entering into a pissing contest. Regardless of what anyone thinks of MRT "we" as Forum users have to thank them for making it public knowledge :brave:

Here's a thought Rexy03, remove the filters from the Banjo bolts and report back the result. Could be $200 well spent.

[QUOTE=maddog]Other competent mechanics have diagnosed this fault, saying who was the first is just entering into a pissing contest. Regardless of what anyone thinks of MRT "we" as Forum users have to thank them for making it public knowledge
Here's a thought Rexy03, remove the filters from the Banjo bolts and report back the result. Could be $200 well spent.[/QUOTE]

What is this fault that MRT has resolved - everyone mentions it but no body has actualy told me what it is - ive assumed it is the removal of the banjo bolt filters
I have just removed the filters after finding this american subaru service bulletin

[url]http://www.scoobymods.com/forums/attachment.php?attachmentid=4272&d=1131460148[/url]

[url]http://www.scoobymods.com/forums/attachment.php?attachmentid=4273&d=1131460154[/url]


Both my filters had fallen down into the soleniod
I havent had an ECU reset but the car is running better day by day
it pulls much harder and the jerky acceleration is much smoother
I should have removed the filters ages ago but they are difficult to get out on the 03 - theres brackets and plumbing over them that makes it hard to even see them

[QUOTE=Rexy03]What is this fault that MRT has resolved - everyone mentions it but no body has actualy told me what it is - ive assumed it is the removal of the banjo bolt filters[/QUOTE]
Yes that is correct.

bumping an old thread as i'm after some info on the AVCS unit in the EJ207's (mine in particular is an MY03 JDM EJ207)

this is my most recent dyno chart from ASG. Sean thinks the funniness in the power band is due to the AVCS not working properly and it may need a clean our or something. Is this a hard job to do? Has anyone else had a similar problem and was able to fix it by cleaning out their avcs solenoid?