Stalling, shuttering when cold

Ever since I have gone to stage two my car will stall every once and awhile when it is cold. If you come up to a redlight it will stay running but idle very low and when you just touch the gas pedal it will either shutter like its going to stall or it may just stall out all together. Starts right back up and then it is usually fine. Once its warmed all the way up I never have any other issues with it. I have bumped the idle up on the ap but that didn't seem to help. Never had this issue during the summer. My car has cobb intake, invidia up pipe and downpipe with magnaflow cat back. The car is a 5EAT running the OTS map from cobb. Any info or what to start with will be appreciated. Thanks

http://legacygt.com/forums/showthread.php/diy-rough-idle-cold-start-cold-temps-lgt-07-09-155325.html

I don't have any codes thrown for system running lean or misfires and my car is a 06 so I don't know if that makes any difference because the link you posted is for 07 and up cars. I can spray some carb cleaner around intake when the car is cold and see if the engine changes then that tells me it has a leak there. Thanks for the post though I hadn't seen that post.

The codes will appear if it's bad enough, you can still have a leak and symtpoms without a code until it gets so bad, to throw a code...The aging 05-06's seem to do it as well, as they get older. Other than that, I suspect maybe you blew a vac hose off and have a little vac leak somewhere. Check the blue T fitting under the intercooler, that hose can blow off at times

That may be the problem. I did get a code for a overboost one time when I was passing someone which maybe blew off a vacuum line? The car seems to still run just fine but I guess if it is a small enough vacuum line it wouldn't cause too much of a issue.

Can you see the blue t without removing the intercooler?

sometimes, if you can look under the IC or you're a giraffe

Was wondering maybe with a small mirror or something. Wasn't sure how close the fitting was to the bottom of the intercooler.

Clean the MAF sensor?? It has IAT in it too.

 

Mac

No I have not cleaned the maf. I just recently bought the car. I did change out the spt intake for the cobb and looked at the maf and it looked clean but I can try and see if that helps as well.

Could be a small manifold leak. O-rings on 05-07 are thinner than 08-09. After time they begin to leak. Cause rough idle and eventually misfires (once bad enough). It will seal itself up as motor heats to operating temp. So, issue is there when cold, but gone once TGV's expand and the o-ring seals again.

Thats what I'm thinking. I work late tonight so when it gets cold I'm going to start it up and spray carb cleaner around the intake where it meets the TGV's and see if the engine speed changes. If it does I know I have a intake leak. I'm also going to try and see if I have blown any vacuum lines under the intercooler. Hoping maybe a mirror and a flashlight will work trying to see the infamous blue t fitting. Just don't want to pull the intercooler for no reason and really hate to put the stock one back on again. Rather pull it and throw it away and go to either front mount or better intercooler. Thanks for everyones input.

If indeed the TGV o-rings are the problem would it be a good time to delete the TGV's? Just would hate to have a problem with them later down the road and then have to pull the manifold again to deal with them. Once they are deleted will the car have to go to a tuner so I will not get a cel for them missing?

the tgv's are unrelated to this issue, nor do they have to be tampered with in order to change the gaskets in question. If you decide to do a tgv delete you'll need a tuner to disable the plethora of codes. The tgv's are bolted to the head using a different set of bolts than the ones holding the manifold to the tgv's. If you go to a dealer and ask for the tgv to manfiold gasket, they'll more than likely give you the tgv to head paper/metal gasket unknowingly. So be armed with part numbers.

I know they are unrelated but was just saying if I was pretty much down to the TGV's was it worth deleting them now. I know some people have said they have had issues with them acting up and getting cels from them.

It's up to you, I'd just clean the flapper plates and spray the shafts with carb cleaner.

BTW, you can change the TGV "O" rings without removing the manifold, remove hardware for the manifold on both sides of manifold @ manifold to TGV area, lift he manifold a bit, grab the little tab on the "O" ring and remove,(4 of them) install the same way. Do them one at a time. Push the manifold down to ensure they are in the manifold/TGV grove, if it feels right and doesn't feel like somethings in the way, go ahead and bolt them down. The Blue "T" fitting is pretty close to engine centerline, under TMIC, trace the line from the BPV, you will find the T at the end of it(if it's connected).

 

R/Mac

Tried spraying carb cleaner around the TGV o rings and no change in engine speed when cold so that eliminates them as a problem. I checked the blue vacuum t right in front of the intercooler and all the lines are hooked up so its not that. Very weird problem? I let the car warm up today completely before I drove it and it didn't act up one time. So its only if you are driving it and come to a stop while its warming up. Then it will stall. Maybe need a different tune?

boost leak test it. there's various threads about to do one. still sounds like an air leak/sealing issue. maybe throttle body hose...no real way to rule it out completely unless you pressurize the intake system to confirm no air leaks can occur.

Thats gonna be my next check. Wondering if I have a crack or issue with the turbo intake boot. I have heard there are very fragile.

starionesir, did you ever figure out the problem? My car is doing exactly the same thing right now.

No I haven't figured it out. I think it is tune related. It does it at the exact same temp everyday when its cold. Right at a quarter way up on the temp gauge. I'm getting the car protuned in a couple weeks so hopefully that will take care of the problem. Does you car stall out at the same temp everytime or does it vary?

I figured mine out. Loose battery cable. Seems fine now.

Good glad to hear it was a simple easy fix.

I was suffering from the same problem for the past week. Today I replaced my purge valve (part # 42084 FE010 I believe) and it appears to have fixed the problem. However it's only been about 2 hours since the replacement, I'll keep you posted if the problem comes back.

 

The purge valve costs about $50-60 CAD.