Idle hang is driving me crazy!

Started having this issue pretty recently. What happens is idle hanging when i depress the clutch. Its mostly evident when i am maneuvering in a parking lot. So lets say i am pulling into a stall and i rev up the engine a little and depress the clutch to shift in to reverse, if i dont turn the steering wheel the rpms drop almost normally but if i am turning the steering wheel and have the clutch depressed the rpm hang at around 1300-1500 until i stop turning the steering wheel.

 

Here is a short video i took. Sorry for shakiness its hard to record and turn the wheel at the same time.

[ame=http://www.youtube.com/watch?v=bqLQBHrT3G0]YouTube - Idle issue with 2008 Subaru Legacy[/ame]

 

Any way to fix this or do i have to live with this for ever?

 

 

Mods: invidia DP, bosal catback, GS bcs, road tuned by a very knowledgeable tuner.

you sure what your seeing isnt just the rpms adjusting based on the load you put on the power steering system when turning the wheel while at or near idle (aka slow maneuvering in a parking lot)? Lot of people make that mistake.

I am sure its part of it but rpm should not stay at 1500 under such low load.

eh, you'd be surprised. doesnt sound to off from what I see on my tach when maneuvering the wheel with no throttle.

 

we'll see what other's input says.

Idle hang is a bit of an issue with modded 08+ LGTs, though it's seen more with larger injectors. What I saw in your video isn't what you would normally see with throttle hang. It would usually be something more along the lines of coming off throttle with the clutch pressed in and the revs drop, but slowly rise to around 2k or more, then drop and rise again. It stops when the throttle is blipped a bit.

Idle hang is a bit of an issue with modded 08+ LGTs, though it's seen more with larger injectors. What I saw in your video isn't what you would normally see with throttle hang. It would usually be something more along the lines of coming off throttle with the clutch pressed in and the revs drop, but slowly rise to around 2k or more, then drop and rise again. It stops when the throttle is blipped a bit.

 

It does that sometime too, but only if I am turning at the same time.

 

If I am just turning the wheel while rpms are at normal level the rpm does not move a bit. Its only if I am turning at the same time.

I have the same problem with my "new" (with 8K Miles) '09 Spec B.

Dealer told me that it was normal Drive-by-wire response. I don't buy that it's normal. When I take my foot off the gas, I would expect the RPM's to drop to idle, not hang at 1500 RPM's, or even increase from 1000 to 1500 RPM's for several seconds before it drops. I even have a little surge of the car if I let the clutch out again before it drops...can't be safest situation.

I have the same problem with my "new" (with 8K Miles) '09 Spec B.

Dealer told me that it was normal Drive-by-wire response. I don't buy that it's normal. When I take my foot off the gas, I would expect the RPM's to drop to idle, not hang at 1500 RPM's, or even increase from 1000 to 1500 RPM's for several seconds before it drops. I even have a little surge of the car if I let the clutch out again before it drops...can't be safest situation.

 

Yep, I get the surge too:-/

Here is a little better video of what's happening. It was really driving me crazy in traffic today.

 

[ame=http://www.youtube.com/watch?v=q3kj3ze-H1Q]YouTube - More of idle hang[/ame]

 

I went to the dealer and they pretty much told me the only thing they can do is flash a new map on it, which does no good for me because I am on a custom stage two map.

Have you tried taking it out of gear when it does this? I've seen the same thing on my 07 5MT and taking it out of gear makes the idle drop to normal. To me it seems like the car is trying to rev match based on learned practices from my normal driving and when it knows its in neutral the only thing it knows to do is idle.

yeah taking out of the gear or releasing the clutch in neutral usually fixes it. This still should not be like that.

I found a hose off on my 05 and it did that fast idle thing. Hooked the

hose back up and its been fine since. vac leak

Agree on the vacuum leak.

No vacuum leaks. I guess i will have to just live with this. I have been doing some research on this issue and it seems like something that can't be fixed. All drive by wire subarus have this issue some have it more some less.

I really need to take a look at my car. I have never noticed this. Maybe I am just used to it and dismissing it as normal. Every car I have had has ben DBW, so maybe I have just grown immune to these things. Next time I am in the car I will take a look and see what mine does and I'll report back. I am also running a pro-tuned Stage 2 LGT. It'll be a good comparison for those of you that are also modded.

Bumping an old thread to ask if anyone has had more insight on this issue. I just noticed my 08 specb doing this. I've been stage 2 for at least 4 years and have never noticed this until now. I'll have to look for a vacuum leak, but the behavior is odd and very similar to what is described here.

 

Idle is higher when the clutch is pressed and the car in gear. If I take the gear out, idle falls back down to 1k. If I put it in gear, it starts doing it again but only when moving (rolling down a hill for example). I notice it's idling faster when I'm cruising to a light while still in gear and pushing the clutch in for example.

Is your A/C or defrost on when you notice it?

Think all you boys who modify their cars will have issues like this sometime or other . Mapping is so complex nowadays that any changes to manufacturer spec are going to invite trouble .

Is your A/C or defrost on when you notice it?

 

Actually, now that I think about it, this happens when A/C is off. It's finally cooling down so I haven't been using the A/C in the last couple of days. It has been on for the past month or more, so maybe that's why. Maybe the ACU is re-learning non-AC idle.

Think all you boys who modify their cars will have issues like this sometime or other . Mapping is so complex nowadays that any changes to manufacturer spec are going to invite trouble .

 

Of course, but we would still like to know why and fix it. After 4 years and 86,000 miles I have had zero issues and this is the first time I see any weird behavior on the car.