Subaru Legacy Forums

Subaru Legacy Forums (http://legacygt.com/forums/index.php)
-   Warranty Issues & Problems (http://legacygt.com/forums/forumdisplay.php?f=48)
-   -   05 LGT "studdering" during low speed acceleration. (http://legacygt.com/forums/showthread.php?t=3932)

Driver72 10-14-2004 01:17 PM

05 LGT "stuttering" during low speed acceleration.
 
Just curious how many people have experienced their LGT's
"studder", "hiccup" whatever you want to call it
during low speed acceleration.

I've personally felt it a couple times now and
both times it took place when leaving a stop sign or light
in 1st or 2nd gear at low rpms when I've applied medium amounts
of throttle inputs.

To be more precise, for those who may not have even paid attention to
it, it goes like this:

Release the clutch and begin to pull away from the light under light
throttle, then you get into the throttle a bit heavier while under
2000 rpm's only to feel a couple quick "studders" or "hiccups" for a
brief second as the the car is accelerating away.
Once you start to get into the boost area 2800 rpms+ it won't happen.

These are not major hesitations or misfires or anything, just small
studdering.

I know many have posted about this before and I've spoke to a couple people
who've experienced this very same thing, but I want to get a better idea
of how many people have had this on their car and if it's a pretty common
05 LGT characteristic. Maybe we can speed up Subaru's resolution by
reflashing the ECU or taking whatever steps are necessary to fix it.

RoundBoy 10-14-2004 01:21 PM

how many miles ?

I wonder if this is a result of your ECU not totally out of the 'safe' zone for knocking....

or if it learned some potentially unoptimized data. maybe a ECU reset and begin again with your driving 'style' ?

Driver72 10-14-2004 01:28 PM

I only have 285 miles on my car even though I've had it for 3 weeks.
I didn't notice it for the first 250 miles, but most of those were freeway
miles going from the dealership to home and then to Star Shield and back
getting my clearbra put on. And yes, I did vary my speed on the freeway
between 60-80 mph and even occasionally shifting it down to 4th while
at 60-65 mph for a little bit.

But once while the car was still relatively cold I noticed it, and then
later after driving it around for 10-15 miles it did it again a couple times.
I wondered if it was the case of it being so new, but others with over their break in miles still get it and I remember reading other posts about this too.
Here's one of them:
http://www.legacygt.com/forums/showt...hlight=studder

I'm hoping it will go away with more break in miles and as the ECU "learns" and adjusts for everything, including the crappy 91 Octane California gas.

Again, I just want to get a better idea of how wide spread it is and how many people it affected and if it "went away" for them as they got more miles on the car. Mine doesn't seem to be that bad or that often, but still even though it's minor and I've only noticed it a couple times, I wouldn't like it if it was there all the time.

05LegacyGT330Ci 10-14-2004 01:31 PM

Happens to me all the time still and I have 51xx miles now. Its annoys me but is a big 4 cylinder with a turbo so oh well.

Driver72 10-14-2004 01:35 PM

I don't think that's an excuse.
They've been turbocharging this motor now for a two years.
And I don't think it's been an issue with the STI or the FXT.

Th3Franz 10-14-2004 01:41 PM

I'm almost at 4000 miles and I still notice it.. :redface:

bemani 10-14-2004 01:50 PM

Shuddering? Only on my WRX.

LandShark 10-14-2004 01:59 PM

Had my LGT 5M for just shy of one month now but beyond 3K miles already. Definitely do notice the "hesitation" as I've called it. And no, its not a misread of the turbo lag affect. It's a legitimate drop in power but very briefly. I've learned to accept it. I find that this car is not enjoyed most by trying to launch it fast from a stand still. This car is best suited for passing wanttabees on the road. I love the way this car blasts away from 50 mph like it was standing still.

Whitestar Pilot 10-14-2004 02:04 PM

I've noticed it a few times while entering expressway ramps.

One time I floored the gas pedal to see if it would stop but the studder continued, I let off at 4500rpm in 3rd because I only had 500 miles on the car.

Lately, approaching 1,000 miles on the car, I've begun to run it a little harder, and most of the time there is no studder.

I wonder if it is an ignition/electrical problem, it makes the car feel like it needs a tune-up, but since this is a new car, obviously it does not.

I also wonder if gutting the up-pipe will solve the issue.

awdG35killer 10-14-2004 02:13 PM

mine does it occasionally, i have 511 miles.

its my first turbo, so its new to me. do really diagnose it we need boost gauges to see wtf is going on. so im not modding until i get one in.

centerpunch 10-14-2004 02:15 PM

Mine does it continuously, it's most noticeable from 2000-3000 rpm, but it does it all the way to redline. Car has 3000+ miles and has always used premium gas.

Very annoying.

thatericguy 10-14-2004 02:22 PM

3600 miles and it happens once in a while. im wondering if its because its runnng too rich? or something with the ecu map setup at low speeds..because i can get on the gas at hi speeds and its fine.

Driver72 10-14-2004 02:32 PM

I was talking to Boostjunkie about it too. He's talked to Subaru about it and I guess they
said there is nothing they can do right now. But I guess they are aware of the "problem" and are going to work on a ECU reflash or something.

But, once I get more than 1000 miles on my car I want to dyno the car and see if it "studders" during the dyno runs, if so, if it can be seen on the dyno plot.
I'm sure it can, because it feels like a few rapid successions of hiccups or something and during that brief period, it definitely doesn't feel like it's accelerating smoothly, therefore it's got to be losing power for ever so brief period before full boost kicks in.

RoundBoy 10-14-2004 02:39 PM

has anyone reset thier ECU in the meantime ?

Can anyone list a method to recreate this reliably ? i am pretty certian this doesn't happen to me

Deer Killer 10-14-2004 03:02 PM

100% reproducible:

1. Put it in 2nd gear, at 2000 rpms. Having lots of passengers and/or going uphill helps

2. Apply between 20% and 50% throttle.

3. Stutter.

WOT may have a hiccup, but it doesn't stutter.

(edit) Perhaps you should put this in your main post, and ask if it stutters when you do this.


All times are GMT -6. The time now is 09:02 PM.


LegacyGT.com