GC8 WRX idling issue

GRK-90D
Learner Driver
Posts: 36
Joined: Wed Jan 04, 2017 12:41 pm

GC8 WRX idling issue

Postby GRK-90D » Sat Feb 04, 2017 7:57 am

Hey everyone,

I've recently had some work done to my car and I'm having an idling issue with the car. It fluctuates between (roughly) 1200rpm down to 200rpm and sometime steadys itself or it stalls. It also (on start up) can rev up to 1200rpm then slowly go down by 200rpm each second passing then stalls.

Basically i got the car retuned within a new blouch 1.5xtr, process west tmic, 1000cc side feed injectors and an e85 tune on the existing ecutek software it has.

My tuner said it was running beautifully on the dyno but once one of his mechanic's took it for a quick road test it started idling funny, like mentioned above.

Has anyone had a similar issue with their GC8 by any chance? I've read up on it and found that it could be multiple things like the O2 sensor, stock air flow box being too restrictive and even the AFM sensor itself.

Any help will be appreciated! I was pulling GREAT numbers on the dyno i just need this issue fixed so its all safe and reliable

mv75
WRX STi Driver
Posts: 810
Joined: Sat Dec 27, 2014 9:26 pm
Location: Brisbane Northside.

Re: GC8 WRX idling issue

Postby mv75 » Sat Feb 04, 2017 9:00 am

AFM or even idle control valve.

GRK-90D
Learner Driver
Posts: 36
Joined: Wed Jan 04, 2017 12:41 pm

Re: GC8 WRX idling issue

Postby GRK-90D » Sat Feb 04, 2017 9:09 am

mv75 wrote:AFM or even idle control valve.



So suggesting a cold air intake? The CAI for a gc8 seem very basic compared to any WRX/STI onwards. The GC8 CAI stops before the actual AFM sensor and the versions onwards actually include the sensor. I want to try and remove as much standard OEM piping to the turbo

stockhorse
Impreza RS Driver
Posts: 212
Joined: Tue Dec 01, 2015 10:44 am
Location: sleeping in the back seat

Re: GC8 WRX idling issue

Postby stockhorse » Sat Feb 04, 2017 10:23 am

" My tuner said it was running beautifully on the dyno but once one of his mechanic's took it for a quick road test it started idling funny, like mentioned above. "

Why didn't your tuner pull the codes and tell you what was at fault?

GRK-90D
Learner Driver
Posts: 36
Joined: Wed Jan 04, 2017 12:41 pm

Re: GC8 WRX idling issue

Postby GRK-90D » Sat Feb 04, 2017 10:30 am

stockhorse wrote:" My tuner said it was running beautifully on the dyno but once one of his mechanic's took it for a quick road test it started idling funny, like mentioned above. "

Why didn't your tuner pull the codes and tell you what was at fault?



Because it was 7pm Friday night, maybe?
I'm not 100% why he couldnt fix it or not but it's Autotech in Sydney and they're well known in Sydney for good reasons. He'll go back in on Monday first thing and see what he can do. It could be multiple things and it seems like it's quite common within GC8s

stockhorse
Impreza RS Driver
Posts: 212
Joined: Tue Dec 01, 2015 10:44 am
Location: sleeping in the back seat

Re: GC8 WRX idling issue

Postby stockhorse » Sat Feb 04, 2017 12:12 pm

Let me see if I am understanding this correctly.
Mods done and tune done on dyno and all looks good.
Taken for test drive and problem found with idle.
It is 7pm Friday night.
Take the car home for the weekend and take it back Monday to be looked at.

GRK-90D
Learner Driver
Posts: 36
Joined: Wed Jan 04, 2017 12:41 pm

Re: GC8 WRX idling issue

Postby GRK-90D » Sat Feb 04, 2017 12:21 pm

stockhorse wrote:Let me see if I am understanding this correctly.
Mods done and tune done on dyno and all looks good.
Taken for test drive and problem found with idle.
It is 7pm Friday night.
Take the car home for the weekend and take it back Monday to be looked at.



Thats right. I couldnt take it home because it kept stalling at idle

mv75
WRX STi Driver
Posts: 810
Joined: Sat Dec 27, 2014 9:26 pm
Location: Brisbane Northside.

Re: GC8 WRX idling issue

Postby mv75 » Sat Feb 04, 2017 3:19 pm

GRK-90D wrote:
mv75 wrote:AFM or even idle control valve.



So suggesting a cold air intake? The CAI for a gc8 seem very basic compared to any WRX/STI onwards. The GC8 CAI stops before the actual AFM sensor and the versions onwards actually include the sensor. I want to try and remove as much standard OEM piping to the turbo


No, I'm saying it might be an air flow meter or idle air control valve error.

The idle valve you can check and clean yourself easily if it's the 99/2000 version. Just two screws and it's out. It's on the very top of the manifold center. Some brake cleaner and a Q-tip will clean out the housing, a bit of paper towel or rag and cleaner to clean the end of the module itself.

Also check your turbo intake pipe. Might have come off or split. Check all pipes.

DIY a cai easily on this model, just remove the snorkel and resonator, then block the snorkel hole.

GRK-90D
Learner Driver
Posts: 36
Joined: Wed Jan 04, 2017 12:41 pm

Re: GC8 WRX idling issue

Postby GRK-90D » Tue Feb 07, 2017 11:37 am

Wow just cleaner out my iacv and i used about 15 ear buds cleaning it out. The first 5 were black as the night! Car felt nice driving an didnt fluctuate in revs at all which is a good sign so far

User avatar
Ezy10z
Learner Driver
Posts: 30
Joined: Thu Oct 28, 2004 9:33 pm

Re: GC8 WRX idling issue

Postby Ezy10z » Mon Mar 06, 2017 10:24 am

Good to hear you fixed the problem. I was just wondering how the response is with the DOM 1.5xtr on your GC8 and what revs do you reach max boost? I'm assuming you have a 2lt and no avcs. Do you run 98 and e85?

User avatar
Delivan
Impreza 22B Driver
Posts: 1800
Joined: Tue Apr 29, 2008 12:18 am
Location: Sitting in the kitchen in Brisbane

Re: GC8 WRX idling issue

Postby Delivan » Mon Mar 06, 2017 12:27 pm

2+ ...DIY a cai easily on this model, just remove the snorkel and resonator, then block the snorkel hole.
This a good free mod that makes a difference to sound and performance..
'09 Impreza Charcoal Hatch Auto
'03 WRX Pearl Red Bug Sedan
'02 WRX Silver Bug Wagon
'98 WRX Blue Club Spec Evo 2 with 2.5 lt
'99 WRX White Sti Version 6 with 2.5 lt
'98 Mitsubishi EVO 5 (kept in the basement)

Return to “Engine, Driveline, Exhausts and Turbos”

Who is online

Users browsing this forum: No registered users and 4 guests