Idle too fast?

joshL · Post by **joshL** » Wed Jan 05, 2005 7:18 am

Hi guys,

I have a 1997 1.4 8v 6N Polo. Recently I had a problem with the car stalling, so I checked the fault codes using Vag-com, but no faults were found. I cleaned out the throttle body, and since then the car starts and whilst standing still, it idles perfectly. As soon as the car moves, even at 2mph, the idle speed sticks at between 1500-2000 rpm!
The car still shows no fault codes. I have also carried out throttle body alignment (which shows ADP OK), with no improvement.

Is it possible to adjust the idle speed using vag-com, or am I heading in the wrong direction?

Any help would be greatly appreciated!!

regs,
J

BenMMellor · Post by **BenMMellor** » Wed Jan 05, 2005 10:44 am

try disconnecting the battery for 20-30 mins.

This will cause the ECU to reset and sort itself out.

I had all the same problems on my 16v. I did all the above and was looking at replacing the temp sensors. Whist it was in getting service work done and the cambelt changed, the mechanics disconnected the battery and it cured the rough idling.

joshL · Post by **joshL** » Wed Jan 05, 2005 12:17 pm

Tried that. Disconnected the battery overnight, but unfortunatley everything was still the same.

I'm not sure if there is a way of resetting the ecu with vag-com.

david burton · Post by **david burton** » Wed Jan 05, 2005 12:48 pm

I have the same problem

i replaced the temp sensor last night and now it's at 2000rpm, before it was at 1300rpm. darn it.

throttle feels a bit sticky, might lube it all up tonight....

david burton · Post by **david burton** » Wed Jan 05, 2005 6:48 pm

Right

The throttle WAS sticky - but onyl because the jubilee clip on the air kit was catching.

Definitely worth having a look anyway, open up the bay and you might need to take air filter off, but just double check your throttle cable isn't sticky or getting caught.

Cheers

joshL · Post by **joshL** » Wed Jan 05, 2005 8:22 pm

Thanks, will check that.

My only concern is that the idle speed drops down to the correct speed as soon as the car comes to a stop. This can be seen when I let the car just role to a stop without touching the accelerator. This makes me believe that there cant be anything catching on the cable, but maybe I'm wrong. I'll check tomorrow.

bstardchild · Post by **bstardchild** » Wed Jan 05, 2005 8:31 pm

joshL wrote:Thanks, will check that.

My only concern is that the idle speed drops down to the correct speed as soon as the car comes to a stop. This can be seen when I let the car just role to a stop without touching the accelerator. This makes me believe that there cant be anything catching on the cable, but maybe I'm wrong. I'll check tomorrow.

Hmmm - I think vacuum maybe assisting the spring closure

cruisin_chris · Post by **cruisin_chris** » Wed Jan 05, 2005 8:34 pm

hit the nail on head ther, had problem with vacuum and linked to idling prob,

joshL · Post by **joshL** » Wed Jan 05, 2005 8:45 pm

Sounds about right, thanks!!

Does anybody know which vacuum part could be causing this? Is there any paricular hose/area I should check?

joshL · Post by **joshL** » Fri Jan 07, 2005 8:19 am

Anyone?

david burton · Post by **david burton** » Fri Jan 07, 2005 11:00 pm

gone a bit quiet here...

I'd just have a look around the throttle body area - I hear there are hoses around there, perhaps investigate there to start with.

joshL · Post by **joshL** » Sat Jan 08, 2005 8:53 am

Thanks!!

Will have a look around. I think I will also take off the throttle body and check the gasket.

joshL · Post by **joshL** » Tue Jan 11, 2005 6:02 pm

After checking all the vacuum pipes etc, I checked the fault codes and got this code:

00537 Lambda (oxygen Sensor) Regulation

11-10 Control Limit not reached-intermittent.

I also unplugged the lambda sensor, which funny enough didnt produce any fault codes in itself, but the idle speed did increase.

Could the lambda sensor cause increased idle speeds?