HELP! Car stalling at idle

[The Internet]

Hi Everyone,
I need some help. My car was running fine up until 2 days ago. It started to randomly buck (lightly) then when I would stop and let it idle the idle was rough. On accelleration the car acts just fine but now as soon as I let off the gas and step on the clutch to come to a stop it will stall. I have not done anything out of the ordinary to the car since I got it.

It's an 05 LGT
5 speed
Stage 2 with a custom tune loaded into my Cobb AP.

I've only had the car for 20 days and it was running fine when I got it. I've flashed the ECU and reinstalled the map but that didn't help.

Any info or help will be HUGE :up:
Thanks

[The Internet]

Forgot to mention.

I don't mind taking it somewhere to have someone look at it, I'd just want to know the best people to bring it to.

[drdabbles]

There is a known ECU issue in most subies. When you reset the ECU by disconnecting the battery, flashing a new map, or by using the reset ecu option on your AP, the car will stall at idle.

The official fix from Subaru is to run the car for at least 20 minutes before driving anywhere that might require you to hit the brakes or steer after dropping to idle. :lol: It's what you'd call a software bug. :D

So, run that bad boy for a while and see if that fixes her. If not, you could have a failing sensor somewhere? :dunno: That'd require an actual diagnosis by someone.

[The Internet]

Thanks! I'll start her up as soon as I get home and see if that works
:fingerscrossed:

[The Internet]

Its still running like crap. :(

[The Internet]

Do you guys/girls think I should try to run the standard Cobb stage 2 setup and see if that does anything or will I just make it worse?

[BG @ BrenTuning]

no theres really no tuning different in stock vs cobb vs custom tuned at idle

you probably have a boost leak or some sort of vacuum issue. let it run for a while if its a fresh flash, turn it on and DONT touch that gas or drive it let it sit for 15 minutes

[subarude]

do you get a check engine light or anything

[The Internet]

The cars been running for a half hour. I sat dow and brought the idle up to 4k rpm then let it drop and the car just died. I'm really lost here.

[subarude]

possibly a bad maf sensor if you bought a forester this wouldn't have happen :rofl:

[BG @ BrenTuning]

check all clamps and lines between airbox and turbo and clean the maf.

[The Internet]

do you get a check engine light or anything

No check engine light.

Any tricks for checking boost or vacuum leaks?

[subarude]

does it have a stock air box or a aftermarket intake

[The Internet]

check all clamps and lines between airbox and turbo and clean the maf.

Will do! Thanks for the help (not you Gabe lol).

I can't look at it tonight because we still have no power but ill check it in the morning.

[subarude]

the only way i know how to check for leaks is to take a pvc cap the size of your inlet tube drill a hole in it so that a tire valve stem fits snuggle in it fit it in the end of your inlet tube and clamp it down then pinch off one hose that goes to a sensor.if you put a little air in the system you will be able to tell which sensor and hose cause it will start rattling and make sure you don't put more then 15lbs of air in the system and then listen for the leak if there is one.but i would start by cleaning the mass air flow sensor first cause they get dirty easily

[batorr]

does it have a stock air box or a aftermarket intake
Better yet does it have a k and n air filter? These kill mao's all the time

[The Internet]

does it have a stock air box or a aftermarket intake

Its the stock airbox with a normal filter. I know I read about cleaning the MAF sensor with somethingh but I don't remember what it is. I am on my Blackberry so searching sucks.

[The Internet]

:dancingbanana:

I blew one of the intake hoses off. I couldn't see it in the dark. I am going to throw a hose clamp on it and call it good. Thanks everyone (you too Gabe :-) ).

It really is great to have a knowledgeable group of people to help out through issues. Bren, when it's time for a tune and upgrade suggestions, I'm coming to see you!

-Mike

[The Internet]

I was wrong. Reconnecting the hose didn't fix it. I connected the hose and let it run for 20 minuted. When I went to turn the car back on after that, it won't even spark now.

[BG @ BrenTuning]

Very odd. Try disconnecting the battery for a bit after the hose fix, fuel trims were probably out of wack from the leak and that will clear it.

Try that.

[The Internet]

Very odd. Try disconnecting the battery for a bit after the hose fix, fuel trims were probably out of wack from the leak and that will clear it.

Try that.

No luck with the battery disconnect. Can someone post the link on cleaning the MAF sensor for me?

[subarude]

buy a can of mass air flow cleaner.the maf sensor is located on top of the air box held on with 2 phillip screws take it out and hose it down with the cleaner

[Hero]

had the same problem with my idle, eventually a CEL came on for the gas cap - got a new one from subaru and it stopped shutting off on me - but, ur not getting a CEL so not sure in ur case

[BG @ BrenTuning]

buy a can of mass air flow cleaner.the maf sensor is located on top of the air box held on with 2 phillip screws take it out and hose it down with the cleaner

make sure you spray up INSIDE it thats where the maf wire is, not the little eyedrop on the outside.

[The Internet]

My buddy is coming over with a can of MAF cleaner. It did finally throw 2 codes:
P0102 (big surprise right?)
P0171 (Lean condition)


On the plus side...My power just came back on so I can work in the garage and use my computer :squee:

[The Internet]

Here is the hose that blew off.
http://i42.photobucket.com/albums/e308/onzrocs/Legacy%20GT/IMGP5643.jpg

[BG @ BrenTuning]

Ok by those codes and what you said it sounds like a massive leak somewhere in the pressurized system, or the maf is dead/dying

if the car wont crank, try disconnecting the maf and see if you have any better luck. The maf might be no good, or the wire is pulled out of it - hence the low circuit. Or it's disconnected. Try unclipping it and inspecting the wires and then re-installing it.

[The Internet]

The MAF works. While the car was (rough) idling, I pulled the harness real quick and the car almost stalled then I threw it back in and it returned to idling rough. I'm still going to clean it and see what it does.

I'm also going to make a PVC intake pipe to check for any other leaks. I think the car is running 22lbs but I need to confirm with the previous owner.

[BG @ BrenTuning]

cobb stage two runs about 16.5 psi. That code is one you get when you unplug the maf or the connection is shoddy so I would take a good hard look at those wires and see if the pins are loose or coming out.

[-GWOOD-]

My buddy is coming over with a can of MAF cleaner. It did finally throw 2 codes:
P0102 (big surprise right?)
P0171 (Lean condition)


On the plus side...My power just came back on so I can work in the garage and use my computer :squee:
Goodluck with that PO171, Bren helped me fix that code on my car today, i would listen to what he says carefully ;)

[The Internet]

Goodluck with that PO171, Bren helped me fix that code on my car today, i would listen to what he says carefully ;)

Without a doubt! I figure since everyone and their brother speak highly of him, it makes sense to listen.

[shtbxr22]

txt sent!

[BG @ BrenTuning]

txt sent!

let this guy help as well since he's local ! :D

We are all here to help.

[The Internet]

So the plan for tonight (after I get this stupid work thing out of the way) it to clean the maf, and pull the intercooler so I can clean the throttlebody. The battery has been disconnected so the computer shouldn't be confused.

Having the intercooler off will be a good chance for me to inspect the rest of the hoses. They are all hidden pretty well since the intercooler is so big.
http://i49.photobucket.com/albums/f277/RobY6298/CarPix2/IMG00107.jpg

[Bu11dogg2]

what BOV is that?

Recirc or atmospheric? how long has it been on the car?

[The Internet]

It's a recirc
I have NO idea how long it has been on there. Is there a reason it would it cause problems now :confused:

I suppose at some point anyone looking in at the engine could have rubbed or turned it.

[Bu11dogg2]

On accelleration the car acts just fine but now as soon as I let off the gas and step on the clutch to come to a stop it will stall.

sat dow and brought the idle up to 4k rpm then let it drop and the car just died. I'm really lost here.

^this points to one of two things IMHO

1. BOV is not functioning properly
2. MAF is not operating properly

Put your stock BPV back on and see if that fix's it.

[javasti2004]

^this points to one of two things IMHO

1. BOV is not functioning properly
2. MAF is not operating properly

Put your stock BPV back on and see if that fix's it.

+1 a bov can cause lots of problems im running one but have herd of some people with bov on newer cars with teh same problem. try eather looking how to adjust it to make sure its right or put the stock one back on if you have one or borrow one see where that gets you. you can also test the maf if you let me know the year and its a leg right i can look it up for ya.

[javasti2004]

+1 a bov can cause lots of problems im running one but have herd of some people with bov on newer cars with teh same problem. try eather looking how to adjust it to make sure its right or put the stock one back on if you have one or borrow one see where that gets you. you can also test the maf if you let me know the year and its a leg right i can look it up for ya.


nvm ill look it up for a 05 leg and get right back to ya

[javasti2004]

it doesnt look like you can check for a voltage but both thoughs codes seem to be pointe to the maf being bad start there hope that helps (to test the maf it looks like you need subarus diag computer)

[shtbxr22]

great success! :up:

[The Internet]

great success! :up:

Thanks for the help dude!:spin:
Not many people would come out at 10:00 to fix a car when they have to go to work the next day. That says alot about you.

After some crafty leak testing by Eric we found that there was actually another hose that had blown off. It was the blow off tube down under the intake. The hose was deformed and slightly widened.

Taking it out for a ride after, made me realize that it may have been leaking slightly for a while. My boost pressure goes up a lot faster than it did before. I also had a great chance to take my new (to me) car apart and "get to know" the inake.

-I pulled off the BOV and took it apart. It was flawless and in perfect working order.
-I cleaned the throttle body. There was no excessive build up of any kind.
-I cleaned the MAF sensor and didn't have to buy a new one :happybanana:


Thanks to everyone for their input.

[BG @ BrenTuning]

Great fix all around. I knew it sounded like a big inlet leak if the car "shuts off" with the maf connected.

time for a new tune :)

[The Internet]

^^^
I know I can't wait to get a new tune. I'd like to get a few more power adders before the next tune.

[The Internet]

If you look to the right side of this picture you can see a blue coupler. The hose going under the intake at the "T" is what popped off.
http://i42.photobucket.com/albums/e308/onzrocs/Legacy%20GT/IMGP5665.jpg

[Bu11dogg2]

glad to hear you got it fixed!

[javasti2004]

nice and cheep fix alot les than a maf would have been

[The Internet]

Yeah I certainly lucked out. It's a good thing eric came to give me a hand.

I do still have some strange slight hesitation under negative boost pressure but I'm gonna ride it out for a few day just to see if it works itself out :lol:

I see a tune in my future. Maybe even before I add more power parts.

[BG @ BrenTuning]

you may want to reset your fuel trims, by disconnecting your battery or reloading your current base map.

your a,b, fuel trim ranges should be all out of wack from that leak - hence your hesitation

[06vtwrx]

I dont mean the thread jack but my 06 wrx is doing a similar thing. it idles at 500RPM then when the fans turn on it goes down to 200 then it hesitates and jumps up to 1200RPM. ive got an invidia bellmouth DP, invidia N1 catback and AP stage 2 map loaded. i had my local subaru dealership look at it and they said that the voltage on my throttle body under load was off and said that i should change the throttle body, but i talked to the subie dealership where i bought the car from and they said that they dont believe its the throttle body. i believe its a vacuum leak myself but im no mechanic. any thoughts? im going to take the car to my family mechanic tomarrow and have the motor compression checked and looked at for vacuum leaks.

[a_sannine]

My Subaru 1996 outback legacy 70.000 miles has been dying , stalling at stop lights (or long idled portions of time) and it is little hard to start again ,
skipping on high ways ( not always )no trouble codes in memory though .
problem doesn't happen all the time intermittent , every once a while .
help please
Thanks
ps: known car hardly been used for the past 5 years, it is like new shape , rides like a dream , problem started 10 days ago .

[Seraphinwolf]

MAF needs to be replaced (try running with it unplugged to verify) it should run better in fail-safe.

[shtbxr22]

:lol:

[98Wagoon]

:lol:


I see what you did there....





:rofl: