Surging around 3K rpm

[dann]

Hey guys,

I have a 2008 Liberty GT-B manual with 127,000km on it now...

Been hunting this down for a while but nothing seems to fix it. When in Sport and Sport# mode,
the surging is more obvious and even more apparent when under load >50% throttle position...

Around 3K-3.5K my lib feels to come off boost and back on, surging rather radically until around 4K
where it still does it, although not as much...Being out of warranty I don't really want to take it to
a dealership as they charge an arm and a leg and have been doing it myself, Spark plugs, coil packs,
injector clean, upper engine clean, new air and oil filter, oil, and timing belt was done 2000km ago.

Has anyone else had this drama? Is it a common thing to do with just a bad tune from factory, or have
I just got unlucky? What would my next angle of attack be? Possible O2 sensor failure/failing? If its
going to end up with needing a tune, I may swell go all out and get the exhaust, new turbo and a tune
as it is currently stock.

[Robbks]

When in Sport and Sport# mode,
the surging is more obvious and even more apparent when under load >50% throttle position...

Around 3K-3.5K my lib feels to come off boost and back on, surging rather radically until around 4K
where it still does it, although not as much...

Has anyone else had this drama? Is it a common thing to do with just a bad tune from factory, or have
I just got unlucky? What would my next angle of attack be? Possible O2 sensor failure/failing?

if you're >50% throttle then the car is not using the o2 sensor for "closed loop" fuelling but may still be making corrections due to other learned fuel trims.
Starting with these simple things.
have a good look around at the vacuum hoses and intake hoses for any cracks/ leaks/ loose clamps or missing connections particularly the line to the fuel pressure Regulator and wastegate actuator
also look for exhaust leaks.

some of these cars did have bad tunes from the factory and bad fuel can make it worse, with the ECU puling timing to compensate which will result in surging.
the knock sensor itself could also be damaged.
Airflow Meter could also be dirty and not reading the correct airflow (was particularly an issue in 99-00 turbo subies)
AVCS solenoid filters could also be clogged and causing erratic behaviour and poor performance, especially in the RPM zone you're experiencing the problem

[Sheik Jabooti]

Hey Dan,

Did you get to the bottom of this problem? I get the same issue but this is after a retune of the DBW (drive by wire) maps.

[Newbie GT]

This is exactly what was happening on the one I was test driving well described!!

Any results ???

[LBR37Y]

i have a stock as a rock GTB and i have the same problem, feels like its not getting enough fuel, but going off my absolute lack of knowledge i cannot give any ideas but VERY VERY keen to know how to get a smooth ride throughout the entire RPM range...

ill be throwing mine into the local mech in the next few days/weeks due to work but ill be watching this thread like a HAWK!!!

[Newbie GT]

Nick let's watch this space as drive a stock GTB and same issue what goes on ???

[LBR37Y]

i have a funny feeling that we won't get to much attention on this thread, maybe its a tune thing??


has yours been doing this the whole time you have had it or is it a new problem?? as min has only got 70,000kms and now 3days in my possession but i noticed it straight away

[Dropz]

This has been covered regularly.
Searching the various engine sections will give alot of results.
This may give you an idea: viewtopic.php?f=17&t=16981

[Newbie GT]

Hi nick it seems to be a common problem ?
What sort of behavior are you experiencing ?

Happy with the power of the GTB? Any pics ? Did you buy from a dealer ?

[LBR37Y]

This has been covered regularly.
Searching the various engine sections will give alot of results.
This may give you an idea: viewtopic.php?f=17&t=16981

thanks Dropz for the reference but this has only brought up more possible ways this could happen, so i think ill just leave it with the mechanic and say check over everything!!

Hi nick it seems to be a common problem ?
What sort of behavior are you experiencing ?

Happy with the power of the GTB? Any pics ? Did you buy from a dealer ?

yea I'm very happy with the power (I'm upgrading from the MY08 2.5i heritage) so I'm very happy...
no pics as the weather has been pretty poor over the past few days but i will get around to it tomorrow hopefully..
and yes i did buy it from a dealer payed 28k on-road with rego till march

the behaviour I'm experiencing is when I'm in S# around 3k to 4k RPM it will stutter and jerk slightly like said previously the turbo kicks in and out again

but i wasn't expecting the engine to behave like this when i want the power it is defiantly one pretty significant down side in my books

[Newbie GT]

Thanks nick yep really disappointing isn't it I'm really hoping someone has that gold answer for us who have experienced this.

Think I saw one on car sales or eBay around that cost .

Fingers crossed we get a fix to this !! Keep in touch

[Newbie GT]

Hmm air flow meter ??

[Dropz]

Afm, air/fuel sensor or o2 sensor are the most common 3 things causing surging/ lack of power. Also dirty throttle body. Remove the intercooler and clean it out. Easy job.

[LBR37Y]

Afm, air/fuel sensor or o2 sensor are the most common 3 things causing surging/ lack of power. Also dirty throttle body. Remove the intercooler and clean it out. Easy job.

i hope that, thats all the problem is!!

[Newbie GT]

Like a misfire on acceratation but not a miss fire hmmm

????