At the mercy off the subie gods and LGT forums

[CanadianLegacyGT]

I'm praying someone can throw ideas at me. Before I begin, I have minimal experience fixing cars so abbreviations and fancy mechanic talk won't help me.

 

I have an 06 legacy gt limited. For the last week it's been parked because it has begun doing something weird. While driving it kind of "chugs"?? I'll be driving along normally, barely feathering the pedal and it'll give me jerking motions. However when I step on it and give it hell it has no problems.. it stalls or drops out rpms to almost stall when coming to a stop.

 

It is throwing NO codes so I'm lost. I've changed the air filter, I bought and changed the MAF. Oil change..i don't know what else to do.

 

Please help!

[Rhitter]

Have you reset the ECU? Checked that all air connections (from air filter all the way to throttle body) are tight?

[CanadianLegacyGT]

I have indeed checked all of that as well as reset the ECU

[Outback2.5XT-05]

Would you describe what it's doing as a "stumble"?

 

If so, nearly all of the ej25x's do it according to the LGT online knowledgebase. I haven't tried it yet but according to others you might want to try the fuel pressure regulator vacuum line relocation (http://legacygt.com/forums/showthread.php/install-04-07-sti-fuel-pressure-regulator-fpr-and-use-263825.html) for a quick and cheap upgrade which might fix this off the bat.

 

Either way, best of luck.

[Infosecdad]

Pull the TMIC and look for the blue tee underneath and it's connection to the intake. It sounds like you have a full vacuum leak and that is a common place that you can't really see without pulling the TMIC.

[CanadianLegacyGT]

I wouldn't call it a stumble, it really is more of a jerk.. because it's consistent while driving. If I hover around 2500rpm it's the most noticeable and starts to go away around 3500

[CanadianLegacyGT]

Pull the TMIC and look for the blue tee underneath and it's connection to the intake. It sounds like you have a full vacuum leak and that is a common place that you can't really see without pulling the TMIC.

 

I'll give it a try on my next day off, thanks for the suggestion.

[FJuan]

I wouldn't call it a stumble, it really is more of a jerk.. because it's consistent while driving. If I hover around 2500rpm it's the most noticeable and starts to go away around 3500

 

That is what we call the typical LGT stumble. There are several threads related to this, so you are not alone. The most common is the Fuel Pressure Regulator (FPR) that needs to be upgraded or the return hose needs to be rerouted. There could be other issues as well like vacuum hoses that has come disconnected. Google Legacy stumble and you should find several results.

[CanadianLegacyGT]

That is what we call the typical LGT stumble. There are several threads related to this, so you are not alone. The most common is the Fuel Pressure Regulator (FPR) that needs to be upgraded or the return hose needs to be rerouted. There could be other issues as well like vacuum hoses that has come disconnected. Google Legacy stumble and you should find several results.

 

 

I need to ask, is it bad to drive with the "stumble"

[FJuan]

No, I drove like that for almost a year until I figured out the issue. The car may go in/out of "limp" mode which is a safety switch to prevent blowing the motor/turbo, you'll only have 50% boost while in "limp" mode. For me it was the fuel return hose that popped off the FPR, something I over looked for months. After reconnecting it, it fix my stumble.

 

Regardless, these cars don't like the lower RPMs while in turbo lag, the ECU has a hard time adjusting air/fuel ratio, especially in the 4th cylinder as several has tested. To really dial it in, you will need to fix the root of the cause and if it still stumbles a little, have a tuner look at your data log. He will be able to adjust for the difference, but only after you have fix the main cause.