Auto question: low idle

[homerjay]

My piece of shit 96 Volkswagen started idling really low last week during the cold snap and now it's still doing it...usually it idles at around 800 rpm but now it's abour 500 and it wants to stall out if it doesn't warm up enough.

Function of very cold weather or something I need to be concerned with?

note: I've had this car for 8 years or so and it's never done this despite other very cold weather. It starts fine, battery is ~ 1yr old.

I fucking suck at car-related stuff. Thanks.

[Big E]

Sounds like something in the idle-enrichment realm. The car should have some sort of "circuit" (not just electrical, but electrical, air, fuel, etc.) that would regulate idle and feed in more fuel when the motor is cold (like a choke on a carbereuted - how the hell do spell that - engin). Could be a bad temp sensor, bad idle air controller, maybe a clogged fuel filter. If you use the pedal to bring it up to 800, is it fine then?

[lemon boy]

have you run some BG 44K through your gas tank lately? Cause you should.

[Core Shot]

www.vwvortex.com
a great VW car forum
They will know for sure.

[ill-advised strategy]

bad idle air controller,

for what it's worth, my subaru has one of these and it makes it hard to slow down when I start the car cold and immediately drive down canyon because it's trying to high-idle and warm up while I'm trying to engine brake. I put a switch into the idle air controller circuit, so as to disable the idle air controller....when I switch it off, the car behaves like you describe. It could be anything Big E described.

and by the way, I was so disappointed to find out that extremo mountain guy avatar wasn't you.

[boar2m]

It could be any number of problems Big E described, or it could be a real simple problem that you can solve in 5 to 10 minutes with zero cost.

So try the most obvious first - Check inside the plastic-tube by "throttle plate". (Throttle plate is a round disk or butterfly on a shaft that allows air into the engine as the accelerator pedal is pushed. There are also electronic sensors (idle control valve) attached to it. Just follow the tube after air-filter and where tube enters the engine block is where the plate is located. If it's dirty (black carbon build up), clean with rag real good and suck any debris out with shop-vac. When car is idling, it does not take much air and tthrottle plate is barely open, and any (air flow) restriction can cause poor air-fuel mix and rough idling and stalling.

[seatosky]

www.vwvortex.com
a great VW car forum
They will know for sure.

Seconded, these guys know their stuff.