Part of the A/C operation is to open the AIC valve some when the A/C clutch engages, to compensate for the load the A/C system places on the engine. Rapid cycling of the A/C clutch could very well cause the engine speed to bounce around.
As others have mentioned, a low refrigerant charge can cause the A/C clutch to cycle on the refrigerant low pressure switch. When the refrigerant charge is low, the clutch initially engages, pressure goes too low, switch opens, clutch disengages, pressure rises, switch closes, clutch engages etc. Normally the compressor should cycle no more than about 4 times a minute. Does the A/C cool well once it stops cycling? If not the refrigerant charge maybe low. Otherwise the A/C relay may need solder joint resoldering, or maybe there is an issue with anti-frost switch, or the refrigerant pressure switch.
posted by 65.101.91...
Posts in this Thread:
Members can receive an alert when someone posts in this thread.
- cold idle issues, Dan Y, Sun, 27 May 2012 09:48:08
- suspect low voltage at main relay, distribution bus, Ken Fisher, Mon, 28 May 2012 17:34:26
- Re: cold idle issues, BobS, Mon, 28 May 2012 14:21:31
- Coolant Temperature Sensor?, Bill Homer, Mon, 28 May 2012 07:50:26
- Re: cold idle issues, Simon S, Sun, 27 May 2012 12:31:20
Post a Followup
The content on this site may not be republished without permission. Copyright © 1988-2012 - The Saab Network - saabnet.com.
This is a moderated bulletin board - Posting is a privilege, not a right.
Unsolicited commercial postings are not allowed (no Spam). Please, no For Sale or Wanted postings, SERIOUSLY.
Classifieds are to be listed in The Saab Network Classifieds pages.
This is a problem solving forum for over 250,000 Saab owners, so expect to see
problems discussed here even though our cars are generally very reliable. This is not an anything goes
type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the
Saabnet.com Mission and Purpose Page. Please remember that you are
not anonymous. Site Donations
Your address is: 22.214.171.124 - Using CCBot/2.0 - Logged.
Site Members do not see red text instructions, green links, and bottom of the page banners.
Click here to see all
the Site Membership Benefits!