2G P0505 Idle Control System Malfunction

[broox]

Car: 95 Eagle Talon Tsi - FWD A/T - 160k miles

Ok so yesterday morning I got in my car and drove to work, everything ran fine. When I got to work and parked, my car was idling really really rough and almost died. Then when I went out for lunch it actually stalled when I backed out. When at idle the tach needle is practically sitting on the pin at 0 RPM.

When I left work, it stalled again. Then when I started back up an engine light finally came on. I took it to Autozone and had them read it. I got P0505 which is an Idle Control System Malfunction.

Now when I get to a stoplight I have to put the car into neutral and rev the car to about 700 RPM just to keep it from dying. haha.

Any ideas what could be going on? Since the light didnt come on right away I was wondering if there is anything it could be besides the idle air control valve. I can't seem to find any problems/leaks in the intake/intercooler visually.

Thanks.

oops, i forgot to add that they cleared the check engine light and it hasn't came on since... but it's still running like hell.

 

[newdsmtnr96]

oops, i forgot to add that they cleared the check engine light and it hasnt came on since... but it's still running like hell.

Hey my car does some thing like that did you check the o2 sencer. im new to dsm and i went to advanced for a free scan and they put some thing on my car and it said it was a 02 heat senser (holds up the paper) this is what it looks like ... well says

vehicle scanned

02 sensor heater circuit malfunction
(bank 1 sen 2)

I dont know if yours is like mine but i been told thats what makes the rpms so low. (advanced person told me) and some others. id check on that tho. Just a guess. i got a miss fire also so it could be that too i think.. low rpms. my eclipse does about 600 to 1000 but every once and a while it will get really low and kinda start to knock.. id do a free scan if i were you just to see what they say. (im still new so if this all sounds stuped you know why

 

[broox]

haha, yo dude. if you read my first post you'd see that i already got the free scan at autozone.

my error was different than yours. thanks for the try though.

 

[broox]

Ok, I just made the IC tester and I'm barely getting 2 PSI on the boost guage. I didn't cap or unplug any tubes/hoses/anything.... So I don't know if I did it entirely right.

But, I can feel some air coming out of the top of the intercooler (stock side mount).... I can't get a great read on it but it seems like it's right near the top bracket of the intercooler.

So...

 

[broox]

Ok, I found some holes. It looks like the bracket on the top of my intercooler was coming loose, and air was getting out of one of these 2 holes where the mounts were.

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I'm going to try to JB Weld those and see if that fixes it. Can holes this small really fix this big of a problem???

 

[broox]

Sorry, I never posted the verdict and people are PMing me for advice.

So....

the IC patch didn't fix it... My problem was that the BISS was not properly set and the ISC was gummed up so bad it could no longer compensate for the variation in the idle range adjustment.

spraying a bunch of cleaner on the ISC, and backing out the BISS a bit solved the problem.

 

[mramc3]

I purchased a new ISC motor and replaced the old one I had on my 96 Tsi AWD. The ISC is newer and is designed differently. I was happy to replace this and avoid any other malfunctions. At the time of replacement, I completely cleaned out the Throttle Body. Might be a good idea to avoid any other problems. And yes I had the same P0505 failure. Long gone.

I did have of problems too with the car running funny. This P0505 error was the prelude of a list of vaccum sensors and pressure sensors that needed to be changed. Hopefully your solved problem will be the only one.