Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Wandering Idle / Excessive Smoke on Cold Start

openwater
 Share

Recommended Posts

openwater Member

openwater

Posted
Posted

'99 base - 71k miles. Two weeks ago the idle would not settle in at the usual 780 after a cold start. Wandered between 800 and 1000 in a random manor. Realized I had not been on the freeway in some time (I live a mile from work) and rarely got up to temperature for prolonged periods this winter. Went on a 40 mile loop at 80 mph or so but idle did not even out. It wandered less, but started to get rough when approaching the typical 780 rpm. Ran a tank with Techron injector cleaner with no change. No pending OBD codes. No loss of power. Noticed excessive white smoke on cold start Saturday. Monday - even more smoke then the idle started going crazy. Pulsing between 850 and 1200 over and over at about a second and a half interval.

Spark plugs changed 8k miles ago. New MAF - 5k miles. New 2nd air system plumbing 2k miles. New oil 2k miles.

Thanks in advance!

  • Moderators
Tool Pants Member

Tool Pants

Posted
  • Moderators
Posted

On the idle issue my guess is the idle stabilizer valve. On a non-egas there is a valve that moves to stablilize the idle. Over time carbon gets in this valve and it does not move freely. The valve is attached to the throttle body. You remove it and clean it with carb cleaner.

This is it on a non-egas 996.

post-4-1173891704_thumb.jpg

wvicary Member

wvicary

Posted
Posted

Has the oil seperator ever been replaced? The part has been updated a few times and can cause both problems.

openwater Member

openwater

Posted
  • Author
Posted
Has the oil seperator ever been replaced? The part has been updated a few times and can cause both problems.

I suspected the oil separator based on previous posts... didn't know it could have this effect on the idle. TP - Is there a gasket required for the re-install of the valve? Difficult to see from the photo. Thanks

Rodger Member

Rodger

Posted
Posted

Looks to me the gasket is stuck to the valve in the pic. Appears to be a green paper/fibrous gasket. I've reused that type plenty of times as long as it's not damaged.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.