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)

Idle bounce or hunting


Recommended Posts

I have a 77 911 SC that has a 83 or 84 3.2L engine that has a newer non CIS fuel injection system. I guess that's the Jetronic system? I'm not really sure. Most of the time the engine runs great except when it is first started. It starts fine but I get a lot of idle bounce or hunting. Aside from the posibilities of vaccumme leaks I was told by a mechanic to lower the idle as my idle is set too high and that could cause the problem. It is currently at around 1200 RPM and should be around 850 RPM. The problem is I'm not sure how to adjust it. I was told it is done by using the hex head screw front and center on the throttle body but first you have to jump out a couple of pins on the diag port. Does anyone know what pins I need to put the jumper on. I tried a few combinations and found a couple the brought the idel up but the rest did nothing. Also when I did jump out the pins and turned the hex head idel screw it did nothing. Is that the actual adjusting screw or is it just a cap and the screw is under it. Any help would be greatly appreciated. If someone has a pin out diagram for the diagnostic port that would be great. Also if you know of a good book on this injection system that would be good also. Thanks.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • 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.