scoobymoz

iTrader: (53)

Can anyone help

My 2001 JDM STI is getting full cam advance at idle after approx 1 minute.

The car runs fine until the the AVCS kicks in then it's lumpy as hell.

This all started when I took the car off the road for a few weeks wile I made some mods (coilovers, spoiler, stereo) wile it was stood in my garage I had the battery disconnected, the car ran fine till I took it off the road and disconnected the battery.

I've had Duncan from racedynamix have a look at it, it was Duncan that found out that it was getting full cam advance at idle, if it weren't for him i would still be in my garage now scratching my head.
Thanks Duncan

I just want to know if any one has came across this problem before and what was the cause of it

Andy.F

I have seen this before where there was a glitch in the map data transfer, if you drive off before the AVCS enables then it will run fine......or get it remapped !

scoobymoz

iTrader: (53)

The car has been mapped Andy.

I have tried an identical standard ECU and the fault is still there but not as aggressive.

bluenose172

iTrader: (2)

Neutral Position Switch?

Pavlo

Sounds more like a faulty avcs solenoid, which can sometimes jam. Also check to see if it's both cams, as that suggests some sort of ECU error. At idle the AVCS isn't active so it shouldn't matter what the neutral switch is doing.

scoobymoz

iTrader: (53)

I don't think it's AVCS solenoids as they are both working, they stay shut for a minute or so then fully open once the car comes off cold start or warms up.

scoobiewrx555

If you have tried a different ECU and still have issues on both banks then it might suggest an issue with the connectors or wiring between the ECU and AVCS modules (moisture causing some kind of short in the wiring until engine is up to temp and moisture evaporates). It's reasonable to assume that the alternative ECU you tried is working 100% and unlikely it had the same issue as your original ECU if there is an issue with it.

If it was just one bank playing up then it's reasonable to assume it might be a module, solenoid or timing controller issue and straightforward enough to isolate the problem.

You could try cleaning the filter in the banjo bolt of the AVCS oil feed, easy enough to do.

Just a thought....have you changed your turbo oil feed banjo bolt from OEM to a normal type banjo bolt as that gets a feed from the same oil line as the AVCS and might cause an issue affecting oil feed to the AVCS. I changed my turbo and used a banjo bolt with bigger holes in it but in my case it hasn't affected AVCS operation.

I've just had a look at the ROMS from a JDM S202 and a UK V.7 STi and there's not a huge amount of difference between them but crucially AVCS advance at idle and right the way up the rev range and up to 0.4g/rev is 0 so hopefully not a mapping issue.

I don't drink often either and just had a couple of glasses of cava so i might be talking ****e!!

dynamix

iTrader: (3)

Andy - it was a car you ecutek mapped iirc. I was in the area so to help moz I hooked up to see what it was doing. The map certainly doesnt show any avcs at idle.

It would start fine, then idle fine but then when it does the avcs alignment both cams would kick in 50/51 degrees of timing and making it run rough as a rough thing.

There was a subaru bulletin to remove the gauze filters from the avcs oil feeds a while back - I advised it may be worth checking these and removing the whole OCV assembly and cleaning - it doesnt take too long.

I didn't try to reflash it.

Andy.F

Reset the ECU, start it, drive off and have a bit load on the engine when it hits the AVCS timer at circa 60 secs, AVCS should blip and then function normally.
Not sure what exactly happens to the cams during a flat battery/extended storage situation but seen it a few times on cars that have turned up for mapping (only on JDM so far) where it needs coaxed back to normal like this.
The fact that a std ECU is doing the same thing suggests its mechanical though, I had previously considered it was an ECU related glitch.

scoobymoz

iTrader: (53)

The car isn't taxed at the moment but i will try and tax the car tomorrow and take it for a drive, off boost to see if the fault clears it's self as suggested by Andy.

Thanks to everyone for the device so far

scoobymoz

iTrader: (53)

Well I got the car taxed today and I took it for a drive and i'm so pleased to say it's now sorted

Big thanks to Andy.F and dynamix for there help

I can't believe that all it needed was to be taken for a drive. The fault seemed really bad, so bad that i wouldn't drive the car because i thought it would do some damage

But it's all sorted now

dynamix

iTrader: (3)

Cool - very pleased it is sorted for you.

Well done Andy for the advice on that one.

scoobiewrx555

You live and learn. Nice one!!

alcazar

iTrader: (2)

Weird...........so does anyone know what causes it?

Andy.F

Happy ending

You tend to pick up handy stuff like this when you have been mapping just Subarus full time for around 8 years lol

Andy

blackandgold scooby

any idea why my avcs only seem to kick in when i flick the heated rear window switch to on





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