Subaru health check day in Collingwood...

[Yowie]

I think Julian Edgar of Autospeed commented on how clean his engine internals were while he was running water injection (probably a diesel, I forget exactly which article series).

[Kimmo]

sturdy gland

hur hur

BeavisandButthead_thumb.jpg (92.94 KiB) Viewed 446 times

[Yowie]

[bigBADbenny]

Seafoam UEC

I use the 3 way method on IWSTI...

I’ll dig up the link if you need:

https://www.iwsti.com/threads/seafoam-y ... ne.179036/

That’s the bov ref hose for the intake.

But I’m considering adding a tee to the map reference hose at the front of the inlet manifold, so I can also hit cyl 1 & 2 better.

My fpr ref is teed to the bov ref hose so I add UEC through that currently.

Since I’ve had the car for so long I’d consider adding a gland to the tmic or throttlebody hose so I can hit the throttlebody and plate with uec too.

As for the brake booster hose, some markets and models have a one way valve in the hose itself which would prevent using it for uec.

This method might work for cars with the one way valve in the booster, not the hose, and only if the hose had a central port on the inlet manifold.

So recently I uec’d/seafoamed my inlet manifold, hadn’t done it for a few years, and bingo: smoke screen!

Its a sure sign of a successful sea foam treatment

[MadmanSean]

Hey guys,

Thought I would post up a little example showing how a health check can help identify potential mechanical issues.

The AVCS system in our EJ20 and EJ25 engines is oil controlled, meaning that an Oil Control Valve (OCV) allows a certain amount of oil to pass through to the cam gear in order to advance (intake ) or retard (exhaust). The amount of degrees applied is based on the electrical Pulse width modulated (PWM) signal received from the ECU.

Example 1:
Here we have Louisa's Preface GT with Dual AVCS (Intake and Exhaust), both Intake and both exhaust cams are perfectly in sync (within 1 or 2 degrees).

Louisa_AVCS

Louisa_AVCS_NSync.JPG (118.67 KiB) Viewed 273 times

Louisa_AVCS2

Louisa_AVCS_NSync2.JPG (119.04 KiB) Viewed 273 times

Example 2:
Here we have another Preface GT with Dual AVCS and we can quickly see that the cams on either side of the engine are not in sync. FYI, this is a freshly put together engine.

JW_AVCS

JW_AVCS_NOSync.JPG (120.99 KiB) Viewed 273 times

How does this effect the overall drivability of the car you ask? Well these being out of sync can cause late spool up of the turbo, misfires due to the cam's being advanced/retarded too much at the wrong time, general jerkiness in applying power when getting on and off the the throttle and surging when cruising can also happen.

AVCS VVT troubleshooting guide here http://forum.liberty.asn.au/viewtopic.php?f=18&t=20233

So get on down to the health check day ASAP to see if your car is performing at it's peak potential

[Yowie]

How does this effect the overall drivability of the car you ask? Well these being out of sync can cause late spool up of the turbo, misfires due to the cam's being advanced/retarded too much at the wrong time, general jerkiness in applying power when getting on and off the the throttle and surging when cruising can also happen.

Confirmed.

My wife's SH Forester had (what turned out to be) a faulty variable inlet cam gear on one bank. Those symptoms were more or less present, albeit "some of the time" The various Subaru mechanics' detection gear reported no issue. Matt (Kido Tune) showed the problem clearly on his laptop.

Perhaps the expensive mechanic diagnostic tools only show the requested cam angle (not the actual cam angle), or perhaps the car happened to perform ok at the moments when the mechanics were checking it.

[bigBADbenny]

Cheers Sean!
I haven’t delved too deeply but the avcs operation/performance specs are way more detailed in the later model FSM’s.
Iirc I glanced at the my15 manual and there’s a lot of detail.

I’ll try to glean the main points and add it to the avcs faq.

I’m waiting to graph Jamie’s recent logs, but as per the avcs faq, vvt angle lag is the first sign of a mild issue.

Then I’d say one banks angle maxing out over the actual requested angle (wind up/overshoot).

After some time we see steady state angle oscillation during cruise.

Once it gets really bad, eg failed ocv, the avcs system cuts out intermittently or completely.

Ime it’s usually the lhs bank 2 ocv that fails first.

I can think of a bunch of potential fixes including swap OCV’s side to side regularly, oil flush, remove banjo bolts...

Or experimental fixes, eg use a common pressure regulated ocv oil supply for the inlet ocv’s, or change the ocv duty cycle in the tune.

Generally, I’ve seen less issues with exhaust avcs, perhaps because the oil is supplied straight from the block via the ocv manifold, the oil pressures are more consistent bank to bank.

[bigBADbenny]

So my car needs a retune as I health checked it, found and fixed deep inlet leaks (bank1/cyl3 cam sensor orings and injector seat seal) on top of usual inlet tract leaks.

I'm using a btssm dash on my stock nav so I'm always aware of my avcs operation, and its going out again after another 150k km.

It's at the intermediate stage: not quite failing altogether, but stuffed and yet not throwing a cel

Its not stumbling yet either, which is interesting...

Anyhow, the game plan is to file off the nubbin on the LHS bank2 banjo bolt avcs oil feed, its tucked in behind the timing cover (see HAMMERDOWN's banjo filter delete post on LGT).

From there I can look for a filter on bank one (postFL so there should be one under the inlet pipe on the turbo/avcs oil feed, or at the ocv itself), then swap OCV's side to side, try some used OCV's from my collection of spares, or just do the right thing and buy a pair of new genuine OCV's from partsouq, flatirons or bennys custom works...

Then I'll fit the Perrin inlet pipe I've had for ages, do an exhaust pressure test (inlet tract confirmed good) and tee up that retune.
I may replace the knock sensor as well as I'm coming up on 300k km!

Here's angle lag:

BBB lag graph.png (52.34 KiB) Viewed 237 times

here's the steady state cruise vvt angle oscillation:

BBB oscillation graph.png (53.48 KiB) Viewed 237 times

Then go look for trending data in scatter graphs of the same log:

Intriguingly, from a quick search it seems that oil temp is a contibuting factor, which suggests in turn I need to dig out the banjo bolt filter on the LHS head, behind the timing cover...

avcs scatter graph.png (62.96 KiB) Viewed 237 times

[bigBADbenny]

Club Lib Subaru health check day in Collingwood!

Same time, same place this Saturday 27/02/21, midday till 4pm.

Little Sams service station cnr Wellington & Sackville Sts

Tuner extraordinaire Sean Regan will be there sanity checking my BS.

Can I ask visitors to please keep the two lanes either side of the fuel bowsers clear for Little Sams esteemed account customers

[Ric]

Bugger, they always come up when I have a prior engagement.
I'll make one of them one of these days