410 replies to this topic

[Robbks]

Lots of good stuff to try there from KONG.

except the advice about taking it to Subaru....


it still surging with wastegate disconnected is a good sign that it's NOT Primary Boost Control related.
So the ECU is still operating the boost control solenoid properly.

Another common issue in boost surging like that is the ECV being prematurely blown open by the Positive Pressure Port on the ECV. this in turn steals boost pressure from the primary turbo, the secondary starts to pre-spool too early and causes issues.
A good test to check this is simply remove and block the vacuum line to the top-port on the ECV.
(this is why we perform the ECV bypass and remove most of this part of the system as it is problematic and useless.)

This is a long and tedious process to test each and every circuit.

Also A silicone intake vastly improves the airflow into the turbo's,
less back-pressure in the intake DOES affect the AFM readings.

It's also plausible that this entire issue is tune related.

[LukeFranky]

Pumped the exhaust full of smoke last night. Nothing spewed out smoke. So that rules out intake and exhaust for low-medium pressure leaks at least. High pressure might be another matter.

 

I'm starting to replace the vac lines one by one and then I'll do the BBOD. I'm not afraid of the BBOD, I've seen inside it.

 

Can I clean the MAP sensor with MAF cleaner?

 

My father, a mechanic, suggested replacing the fuel filter too.

 

Right now, my strategy is to do everything I can test myself without spending too much more money. If I exhaust all possibilities on my own then I will turn to deeper diagnostics and tuning.

[Robbks]

Cleaning the MAP is best done with UEC when you do the Solenoids and vents in the BBod
it's fed by dirty intake air and is subject to blow-by gunk just like the rest of the hoses and solenoids.

Subaru will plug in a code-reader and just start replacing sensors in the hope it fixes the issue.

unless you take it to a specialist workshop.
But at $80-$120 an hour, it's costly.

I maintain the lean-outs is caused by the tune, but I believe the surging is TT control system related.

Do you have a Tactrix or other VAG-COM cable that you can use to view and log live sensor data??

If not, you're chasing your tail.

[LukeFranky]

I looked at buying a VAG-COM a while ago, but I wasn't sure if there was a specific one I should get. Can you suggest one?

[Robbks]

I've used a generic ebay one on my MY03 Liberty RX, MY06 Liberty H6 and 99 GT Forester
It doesn;t work on my CANBUS MY10 Forester,
there's a huge thread on LGT.com here
http://legacygt.com/...alog-96737.html

[duncanm]

You need a VAG-COM with the right chipset....

 

(rummaging around in my old thread...)

 

look for one with a  FT232BL chipset. This worked for me using freeSSM on a JDM ECM

http://www.subyclub....-12#entry516176

 

An ELM237 did *not* work for me.

 

Plenty on ebay for about $12

[LukeFranky]

Managed to bid on one with FT232BL and win for less than $8.

Replacing the vac lines going to the boost controller in the wheel arch. Looked at what lines went where and then promptly forgot. Anyone know which way around they go? It's hard to tell from diagrams.

I think the wastegate line goes to the side, and the intake pipe line goes to the bottom?

[duncanm]

Managed to bid on one with FT232BL and win for less than $8.

Replacing the vac lines going to the boost controller in the wheel arch. Looked at what lines went where and then promptly forgot. Anyone know which way around they go? It's hard to tell from diagrams.

I think the wastegate line goes to the side, and the intake pipe line goes to the bottom?

 

don't think it matters - its just an open/shut valve.

[Robbks]

your problem lies not in the Primary wastegate control lines.
we tested that by disconnecting the wategate and the surge remained.

it's in the ECV, ICV, BPV zone.

Most likely the ECV Duty Solenoid,
it's always been an issue as the line that feeds it comes from under the intercooler which always fiils up with blow-by gunk.
that clogs the duty solenoid and the restrictors in that circuit

 

[LukeFranky]

Yes, I realise that. Just started replacing vac lines on that side first.

[LukeFranky]

Right. Disconnected and blocked the top line on the ECV. No surging!

Did pick a too lean code at the top of a few long hills.

[Robbks]

OK, now as another test,

connect that line to the one that connects to the U-shaped plastic connector right near the secondary BPV.


Also, do you have an adjustable fuel reg??
If so, wind it up a couple of PSI to prevent it leaning out

[LukeFranky]

So I should T off the top of the ECV to the U piece spout?

 

I'm not sure about the fuel regulator on this car. Where is it located?

 

How did you go about fixing that bit after you snapped the nipple off?

 

Is it air tight & holding up OK?

- I used a stepped metal spout to replace the plastic nipple and used a RapidFix to secure and seal it. RapidFix combines finely grounded glass/sand to build up the surface with a strong liquid glue. It is solid and well sealed.

[Robbks]

yep, use a Tee as pictured

Fuel reg is on the back of the manifold.

An Aftermarket one is usually mounted up high at the rear between manifold and fuel filter area.

I suggest you don;t have one.

[LukeFranky]

An Aftermarket one is usually mounted up high at the rear between manifold and fuel filter area.

- Nup, nothing non-stock there. The only fuel reg that I know of lives under the passenger side of the manifold.

[LukeFranky]

I T'd it off like suggested. I assume I was simply supposed to block off the hose going to the differential sensor behind the intercooler?

Anyway, no surging whatsoever. Pulled up a too lean pretty quickly but the turbos seemed to be staging better.