Stumble/Shudder at idle and around 1500rpm

[RaS11M]

Hi Everyone,

I really hope someone can help me with this, The car has been to 6 different mechanics (Ultratune,NRG,Vince Rigoli,JEM,Chester Hill Auto and Subaru Mcgrath) including Subaru Mcgrath and no one seems to be able to resolve the issue.

The issues started shortly after 75000 kms and the car now has 82000. It's a 2004 Subaru Liberty GT MY05 Manual.

The issue is car shudders/stumbles at idle especially when warmed up and when the revs are kept at around 1500rpm the whole car shakes. Normal/on boost driving seems fine, the car pulls like a train.

I am very frustrated with it and at a point I want to actually get rid of it.

The mods on the car:

Phat Dump Pipe
Xforce Catback
with Standard mufflers
Matt (Kido) Tune
Car makes 169kw at all fours (JEM Dyno)

So far This is what has been done on the car:

Front O2 sensor replaced (with an updated OEM one)
Rear O2 sensor replaced (with OEM one)
MAF Sensor replaced (with OEM one)
MAP Sensor replaced (with OEM one)
Injectors pulled out inspected/cleaned/flow tested and put back in the car
Intank Fuel Filter replaced
Spark Plugs replaced with Brand new ones
Coil Pack inspected and checked.
Air Filter replaced (with OEM one)
AVCS Solenoids Pulled out inspected / cleaned and put back in the car all 4 of them
Checked for Vacuum Leaks/Smoke Test done
Compression test done (All with in specs)
Regular Services done on time with Royal purple oil (5W-30) and only OEM parts used including upper Cylinder Cleaner
Timing belt with new tensioner and pulleys done (Dayco Kit)
Water pump replaced (After market)
Always used Shell v-power 98
No Check engine light no diagnostic errors on ECU


Learning view Screen shot can be found here:

Learning View_SS_A2WD002T_2014-09-04 17 36 00.jpg (74.47 KiB) Viewed 4325 times

Rom raider Logs can be found here:
http://1drv.ms/1lRCTWg

Please help me!!!

[Sean82]

My first question is why the hell does the torque and thus the power curve look the way it does ???
That's terrible IMO.

Have you tried setting it back to the factory tune at all?

EDIT: I personally can't look at your logs because I don't have a MS account (that I know of at least)

[jslayz]

PCV issue?

[dazzz168]

Have u tried putting the stock tune back on and seeing if it's normal again?

[alexeiwoody]

What has your tuner said?

What's going on with your Learing View fuel trims? Either the Maf scaling is way off, or something is causing it to adapt like poo. Should be able to zero in on the problem from that.

[dazzz168]

Yup! It's running lean at cruise and looks like AFL D has been disabled so WOT could be potentially damaging...

[RaS11M]

My first question is why the hell does the torque and thus the power curve look the way it does ???
That's terrible IMO.

Have you tried setting it back to the factory tune at all?

EDIT: I personally can't look at your logs because I don't have a MS account (that I know of at least)

It looks a little weird on the dyno sheet but can't really feel it during acceleration, Matt has already fixed torque curve issue since the dyno.

Next is the stock tune on the list just waiting for Matt to get back to Sydney.

[RaS11M]

PCV issue?

This gives me another avenue to try thanks for that mate, no one mentioned that, I have done a bit of a research and it pretty easy to DIY!

Here is a description on bad PCV valve.

At an idle, engine speed is low, around 600 RPM. A relatively small amount of fuel and air travel through the intake at idle speed. If the PCV valve did not regulate air flow, the engine would act like it had a vacuum leak. Too much air flowing into the intake causes the engine to lean out [too much air in relation to the fuel] and misfire. At an idle, the PCV valve restricts air flow, to reduce this problem. At high manifold vacuum [idle], a spring loaded valve is drawn up and partially restricts flow to the crankcase. The first drawing above illustrates the PCV valve position at idle.

and this video shows you how to do it : http://www.youtube.com/watch?v=v3Djx-kTJik

Is this a common known issue on our cars?

Cheers,

Ras

[RaS11M]

What has your tuner said?

What's going on with your Learing View fuel trims? Either the Maf scaling is way off, or something is causing it to adapt like poo. Should be able to zero in on the problem from that.

Tuner is unable to diagnose the issue at this stage. We don't know whats causing the fuel trims to go weird like that.

Cheers

Ras

[Sean82]

My first question is why the hell does the torque and thus the power curve look the way it does ???
That's terrible IMO.

Have you tried setting it back to the factory tune at all?

EDIT: I personally can't look at your logs because I don't have a MS account (that I know of at least)

It looks a little weird on the dyno sheet but can really feel it during acceleration, Matt has already fixed torque curve issue since the dyno.

Next is the stock tune on the list just waiting for Matt to get back to Sydney.

I can give you a hand with flashing in the stock tune and doing some logs to send to Matt.

I'm at Camden, PM me if you'd like any help with it.

[KiDo_Tuning]

Stock tune was actually worse for AF learning, it was +22% but most of the early LGT's are similar numbers from factory.

Yup! It's running lean at cruise and looks like AFL D has been disabled so WOT could be potentially damaging...

It is actually running rich at cruise(smells of it, even when LV is reset) and the WOT AFR's were spot on as per wideband and also the dyno graph.

Cam gears were off target on the tune hence the oscillations on the dyno(adjusted the OCV duty tables to get onto target, hello Dayco timing belt)

PCV was my thought as well, it was inconsistent though. Zac and Ray, both in Canberra have an almost identical car/build

[RaS11M]

Just wanted to confirm , is this the pcv valve ?

pcv valve.JPG (79.71 KiB) Viewed 4225 times

Cheers

Ras

[Sean82]

That's part of the PCV system, but the actual valve that is potentially causing the issue is "11810"

[RaS11M]

That look a little different to the one I thought.

[RaS11M]

That's part of the PCV system, but the actual valve that is potentially causing the issue is "11810"

Do you have a part number for it ?

Cheers

Ras